Re: WANTED: kernel projects for CS students

2007-11-03 Thread david

On Fri, 2 Nov 2007, Rik van Riel wrote:


On Fri, 02 Nov 2007 23:08:23 -0400
[EMAIL PROTECTED] wrote:


IBM's AIX supported file system compression on the JFS filesystem
years ago. I was able to get up to 30% throughput increases by
converting the /usr filesystem to compressed - because even a 33mhz
Power chipset could read in 5 512-byte blocks and decompress it to
the original 4K faster than the disk could read in 8 512-byte
blocks.



Given that today there's an even *bigger* disparity in CPU speed
versus disk speed, I'd be surprised if it doesn't help today too.


The problem is that disk seek times have not gotten much
faster over the years, while disk throughput rates have
skyrocketed.

Transferring a little less data is not going to help you
when 80% of your disk time is spent seeking, not reading
or writing.


however, if you can manage to avoid seeks by packing more data onto each 
track (or each stripe of a raid array) you could probably see a 
significant win


that's something for aspiring (and experianced) filesystem designers to 
struggle with for a while (especially trying to figure out what the size 
of a track or stripe is for the optimal layout)


David Lang
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-11-03 Thread Wander Winkelhorst
On 11/3/07, Rik van Riel <[EMAIL PROTECTED]> wrote:
> On Fri, 02 Nov 2007 23:08:23 -0400
> [EMAIL PROTECTED] wrote:
>
> > IBM's AIX supported file system compression on the JFS filesystem
> > years ago. I was able to get up to 30% throughput increases by
> > converting the /usr filesystem to compressed - because even a 33mhz
> > Power chipset could read in 5 512-byte blocks and decompress it to
> > the original 4K faster than the disk could read in 8 512-byte
> > blocks.
>
> > Given that today there's an even *bigger* disparity in CPU speed
> > versus disk speed, I'd be surprised if it doesn't help today too.
>
> The problem is that disk seek times have not gotten much
> faster over the years, while disk throughput rates have
> skyrocketed.
>
> Transferring a little less data is not going to help you
> when 80% of your disk time is spent seeking, not reading
> or writing.

This sounds like flash based media are an ideal candidate for compression.
No seek times to speak of, transfer rates that are lower than those of
disks and limited capacity.

I believe JFFS2 (a flash filesystem) allready does compression though.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-11-03 Thread Wander Winkelhorst
On 11/3/07, Rik van Riel [EMAIL PROTECTED] wrote:
 On Fri, 02 Nov 2007 23:08:23 -0400
 [EMAIL PROTECTED] wrote:

  IBM's AIX supported file system compression on the JFS filesystem
  years ago. I was able to get up to 30% throughput increases by
  converting the /usr filesystem to compressed - because even a 33mhz
  Power chipset could read in 5 512-byte blocks and decompress it to
  the original 4K faster than the disk could read in 8 512-byte
  blocks.

  Given that today there's an even *bigger* disparity in CPU speed
  versus disk speed, I'd be surprised if it doesn't help today too.

 The problem is that disk seek times have not gotten much
 faster over the years, while disk throughput rates have
 skyrocketed.

 Transferring a little less data is not going to help you
 when 80% of your disk time is spent seeking, not reading
 or writing.

This sounds like flash based media are an ideal candidate for compression.
No seek times to speak of, transfer rates that are lower than those of
disks and limited capacity.

I believe JFFS2 (a flash filesystem) allready does compression though.
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-11-03 Thread david

On Fri, 2 Nov 2007, Rik van Riel wrote:


On Fri, 02 Nov 2007 23:08:23 -0400
[EMAIL PROTECTED] wrote:


IBM's AIX supported file system compression on the JFS filesystem
years ago. I was able to get up to 30% throughput increases by
converting the /usr filesystem to compressed - because even a 33mhz
Power chipset could read in 5 512-byte blocks and decompress it to
the original 4K faster than the disk could read in 8 512-byte
blocks.



Given that today there's an even *bigger* disparity in CPU speed
versus disk speed, I'd be surprised if it doesn't help today too.


The problem is that disk seek times have not gotten much
faster over the years, while disk throughput rates have
skyrocketed.

Transferring a little less data is not going to help you
when 80% of your disk time is spent seeking, not reading
or writing.


however, if you can manage to avoid seeks by packing more data onto each 
track (or each stripe of a raid array) you could probably see a 
significant win


that's something for aspiring (and experianced) filesystem designers to 
struggle with for a while (especially trying to figure out what the size 
of a track or stripe is for the optimal layout)


David Lang
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-11-02 Thread Rik van Riel
On Fri, 02 Nov 2007 23:08:23 -0400
[EMAIL PROTECTED] wrote:

> IBM's AIX supported file system compression on the JFS filesystem
> years ago. I was able to get up to 30% throughput increases by
> converting the /usr filesystem to compressed - because even a 33mhz
> Power chipset could read in 5 512-byte blocks and decompress it to
> the original 4K faster than the disk could read in 8 512-byte
> blocks. 

> Given that today there's an even *bigger* disparity in CPU speed
> versus disk speed, I'd be surprised if it doesn't help today too.

The problem is that disk seek times have not gotten much
faster over the years, while disk throughput rates have
skyrocketed.

Transferring a little less data is not going to help you
when 80% of your disk time is spent seeking, not reading
or writing.

-- 
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-11-02 Thread Valdis . Kletnieks
On Mon, 29 Oct 2007 17:44:52 EDT, Lennart Sorensen said:
> On Mon, Oct 29, 2007 at 09:19:11PM +0100, Pavel Machek wrote:

Sorry for the late reply, it's been a zoo of a week here... ;)

> If it doesn't it seems the compression feature is going to be rather
> unpredictable and my optimization would be perfectly within spec and
> make it pretty much useless.
> 
> > Yes. Typically for all zeros. It will be similar for
> > highly-compressible data (pictures, timetables, )

And most executables.  There's a reason why my vmlinux files are 11M and my
vmlinuz files are 2m. :)

> That would make it tricky to say if you should ever skip compression due
> to cpu load.  There is a chance cpu load would be better off by doing
> the compression.

IBM's AIX supported file system compression on the JFS filesystem years ago. I
was able to get up to 30% throughput increases by converting the /usr
filesystem to compressed - because even a 33mhz Power chipset could read in 5
512-byte blocks and decompress it to the original 4K faster than the disk could
read in 8 512-byte blocks.  Oh, and it worked for compression on r/w workloads
as well - that was one of the ways to get a RS6K model 250 (which was a
PowerPC601 chipset, a dead heat with a Mac 6600 (same chipset, same clock) to
handle a million e-mail msgs/day - even /var/spool/mqueue worked better.

Given that today there's an even *bigger* disparity in CPU speed versus disk
speed, I'd be surprised if it doesn't help today too.  As a first try, you
might consider compressing each 4K filesystem block in-place, and only write as
many sectors as the compressed takes (with the obvious fix for the pathological
"grows with compression" case of "just write it without").  Probably even
more wins can be found if you find a way to store the compressed chunks in a
way that minimizes seeks, but that's a filesystem design issue and probably
a too-large project (It's easy to do the stupid way - just store the whole
file as compressed - the tough part is doing it and not making lseek() *too*
painful.  Trying to figure out where in a .gz file byte 65536... ouch. ;)



pgpnfc9Se5Swi.pgp
Description: PGP signature


Re: WANTED: kernel projects for CS students

2007-11-02 Thread Giacomo Catenazzi
Rik van Riel wrote:
> On Tue, 16 Oct 2007 22:09:04 +0200 (CEST)
> Jan Engelhardt <[EMAIL PROTECTED]> wrote:
>> On Oct 16 2007 13:06, Mark Gross wrote:
>>> base function:
>>> Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
>>> kernel.org tree and automatically create a .config with all the
>>> drivers needed for the platform I'm building on.
>> Too easy. Since opensuse's udev loads most of the modules for your
>> hardware, all that would be needed is to transform the lsmod list of
>> modules plus the static options in /proc/config.gz (stuff like
>> psmouse) back into kconfig options ;-)
> 
> Well, at that point it does not know whether or not you
> occasionally plug in an ipod or a digital camera.
> 
> Going back from the lsmod output to all the right CONFIG
> options is also not as trivial as it sounds, due to all
> the dependencies there are.

As part of Linux Kernel Driver DataBase, yesterday I "solved"
also this problem:
>From a module name, I can obtain relative the kernel
configuration item.

You can see the result in http://cateee.net/lkddb
(grep '^drv module' drivers-db). I count 2570 such items.

But I've some problems on few cases:
sometime there is one module name with more CONFIG_s.
Normally such cases happens in modules on the same directory,
as support module or as parent module.
I don't see a method to distinguish the right (minimal)
configuration.

One solution would be to remove some dependencies on
Makefile, and checking and ev. creating such dependencies
on Kconfig. But this require a kernel modification.

Or you think there is a better (non-invasive) method?

ciao
cate

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-11-02 Thread Giacomo Catenazzi
Rik van Riel wrote:
 On Tue, 16 Oct 2007 22:09:04 +0200 (CEST)
 Jan Engelhardt [EMAIL PROTECTED] wrote:
 On Oct 16 2007 13:06, Mark Gross wrote:
 base function:
 Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
 kernel.org tree and automatically create a .config with all the
 drivers needed for the platform I'm building on.
 Too easy. Since opensuse's udev loads most of the modules for your
 hardware, all that would be needed is to transform the lsmod list of
 modules plus the static options in /proc/config.gz (stuff like
 psmouse) back into kconfig options ;-)
 
 Well, at that point it does not know whether or not you
 occasionally plug in an ipod or a digital camera.
 
 Going back from the lsmod output to all the right CONFIG
 options is also not as trivial as it sounds, due to all
 the dependencies there are.

As part of Linux Kernel Driver DataBase, yesterday I solved
also this problem:
From a module name, I can obtain relative the kernel
configuration item.

You can see the result in http://cateee.net/lkddb
(grep '^drv module' drivers-db). I count 2570 such items.

But I've some problems on few cases:
sometime there is one module name with more CONFIG_s.
Normally such cases happens in modules on the same directory,
as support module or as parent module.
I don't see a method to distinguish the right (minimal)
configuration.

One solution would be to remove some dependencies on
Makefile, and checking and ev. creating such dependencies
on Kconfig. But this require a kernel modification.

Or you think there is a better (non-invasive) method?

ciao
cate

-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-11-02 Thread Valdis . Kletnieks
On Mon, 29 Oct 2007 17:44:52 EDT, Lennart Sorensen said:
 On Mon, Oct 29, 2007 at 09:19:11PM +0100, Pavel Machek wrote:

Sorry for the late reply, it's been a zoo of a week here... ;)

 If it doesn't it seems the compression feature is going to be rather
 unpredictable and my optimization would be perfectly within spec and
 make it pretty much useless.
 
  Yes. Typically for all zeros. It will be similar for
  highly-compressible data (pictures, timetables, )

And most executables.  There's a reason why my vmlinux files are 11M and my
vmlinuz files are 2m. :)

 That would make it tricky to say if you should ever skip compression due
 to cpu load.  There is a chance cpu load would be better off by doing
 the compression.

IBM's AIX supported file system compression on the JFS filesystem years ago. I
was able to get up to 30% throughput increases by converting the /usr
filesystem to compressed - because even a 33mhz Power chipset could read in 5
512-byte blocks and decompress it to the original 4K faster than the disk could
read in 8 512-byte blocks.  Oh, and it worked for compression on r/w workloads
as well - that was one of the ways to get a RS6K model 250 (which was a
PowerPC601 chipset, a dead heat with a Mac 6600 (same chipset, same clock) to
handle a million e-mail msgs/day - even /var/spool/mqueue worked better.

Given that today there's an even *bigger* disparity in CPU speed versus disk
speed, I'd be surprised if it doesn't help today too.  As a first try, you
might consider compressing each 4K filesystem block in-place, and only write as
many sectors as the compressed takes (with the obvious fix for the pathological
grows with compression case of just write it without).  Probably even
more wins can be found if you find a way to store the compressed chunks in a
way that minimizes seeks, but that's a filesystem design issue and probably
a too-large project (It's easy to do the stupid way - just store the whole
file as compressed - the tough part is doing it and not making lseek() *too*
painful.  Trying to figure out where in a .gz file byte 65536... ouch. ;)



pgpnfc9Se5Swi.pgp
Description: PGP signature


Re: WANTED: kernel projects for CS students

2007-11-02 Thread Rik van Riel
On Fri, 02 Nov 2007 23:08:23 -0400
[EMAIL PROTECTED] wrote:

 IBM's AIX supported file system compression on the JFS filesystem
 years ago. I was able to get up to 30% throughput increases by
 converting the /usr filesystem to compressed - because even a 33mhz
 Power chipset could read in 5 512-byte blocks and decompress it to
 the original 4K faster than the disk could read in 8 512-byte
 blocks. 

 Given that today there's an even *bigger* disparity in CPU speed
 versus disk speed, I'd be surprised if it doesn't help today too.

The problem is that disk seek times have not gotten much
faster over the years, while disk throughput rates have
skyrocketed.

Transferring a little less data is not going to help you
when 80% of your disk time is spent seeking, not reading
or writing.

-- 
Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it. - Brian W. Kernighan
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-29 Thread Lennart Sorensen
On Mon, Oct 29, 2007 at 09:19:11PM +0100, Pavel Machek wrote:
> Tell it to your profesor ;-).

I don't have one.  I graduated 7 years ago.  I was just pointing holes
in the spec. :)

> Not neccessarily but yes, that would be nice, too.

If it doesn't it seems the compression feature is going to be rather
unpredictable and my optimization would be perfectly within spec and
make it pretty much useless.

> Yes. Typically for all zeros. It will be similar for
> highly-compressible data (pictures, timetables, )

That would make it tricky to say if you should ever skip compression due
to cpu load.  There is a chance cpu load would be better off by doing
the compression.

> [EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 > 
> delme; sync )
> 0.04user 0.48system 6.52 (0m6.521s) elapsed 7.97%CPU
> [EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 > 
> delme; sync )
> 0.05user 0.61system 6.33 (0m6.333s) elapsed 10.42%CPU
> [EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 | gzip 
> - > delme; sync )
> 1.57user 0.32system 1.74 (0m1.749s) elapsed 100.00%CPU
> [EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 | gzip 
> - > delme; sync )
> 1.61user 0.18system 1.65 (0m1.652s) elapsed 100.00%CPU

--
Len Sorensen
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-29 Thread Pavel Machek
On Mon 2007-10-29 15:48:20, Lennart Sorensen wrote:
> On Sun, Oct 28, 2007 at 06:07:07PM +, Pavel Machek wrote:
> > Hard stuff:
> > 
> > * network character device -- similar to nbd, but for char devices.
> >   either figure out how to forward ioctls(), or implement
> >   usb-over-network, or...
> > 
> > * openMosix -- they seem to have userspace solution, but not GPLed.
> > 
> > * compression for ext4. Its about time someone did it right. Special
> >   bonus if you can do it in a way that it does not slow down. If cpu
> >   is free, compress, if it is busy, just write it straight to disk.
> 
> So if I decide that the cpu is busy (because something is asking me to
> write the cpu is clearly doing something and hence busy), then I can
> skip compression and just write to disk.  So by that definition ext4
> already does compression.  What a simple project. :)

Tell it to your profesor ;-).

> Did you mean it ought to come back and do the compression later?

Not neccessarily but yes, that would be nice, too.

> Is it possible that for some data compressing it and writing will take
> less time than not compressing it and writing it to disk?

Yes. Typically for all zeros. It will be similar for
highly-compressible data (pictures, timetables, )

[EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 > delme; 
sync )
0.04user 0.48system 6.52 (0m6.521s) elapsed 7.97%CPU
[EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 > delme; 
sync )
0.05user 0.61system 6.33 (0m6.333s) elapsed 10.42%CPU
[EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 | gzip - 
> delme; sync )
1.57user 0.32system 1.74 (0m1.749s) elapsed 100.00%CPU
[EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 | gzip - 
> delme; sync )
1.61user 0.18system 1.65 (0m1.652s) elapsed 100.00%CPU

Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) 
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-29 Thread Lennart Sorensen
On Sun, Oct 28, 2007 at 06:07:07PM +, Pavel Machek wrote:
> Hard stuff:
> 
> * network character device -- similar to nbd, but for char devices.
>   either figure out how to forward ioctls(), or implement
>   usb-over-network, or...
> 
> * openMosix -- they seem to have userspace solution, but not GPLed.
> 
> * compression for ext4. Its about time someone did it right. Special
>   bonus if you can do it in a way that it does not slow down. If cpu
>   is free, compress, if it is busy, just write it straight to disk.

So if I decide that the cpu is busy (because something is asking me to
write the cpu is clearly doing something and hence busy), then I can
skip compression and just write to disk.  So by that definition ext4
already does compression.  What a simple project. :)

Did you mean it ought to come back and do the compression later?

Is it possible that for some data compressing it and writing will take
less time than not compressing it and writing it to disk?

--
Len Sorensen
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-29 Thread Pavel Machek
On Mon 2007-10-29 15:48:20, Lennart Sorensen wrote:
 On Sun, Oct 28, 2007 at 06:07:07PM +, Pavel Machek wrote:
  Hard stuff:
  
  * network character device -- similar to nbd, but for char devices.
either figure out how to forward ioctls(), or implement
usb-over-network, or...
  
  * openMosix -- they seem to have userspace solution, but not GPLed.
  
  * compression for ext4. Its about time someone did it right. Special
bonus if you can do it in a way that it does not slow down. If cpu
is free, compress, if it is busy, just write it straight to disk.
 
 So if I decide that the cpu is busy (because something is asking me to
 write the cpu is clearly doing something and hence busy), then I can
 skip compression and just write to disk.  So by that definition ext4
 already does compression.  What a simple project. :)

Tell it to your profesor ;-).

 Did you mean it ought to come back and do the compression later?

Not neccessarily but yes, that would be nice, too.

 Is it possible that for some data compressing it and writing will take
 less time than not compressing it and writing it to disk?

Yes. Typically for all zeros. It will be similar for
highly-compressible data (pictures, timetables, )

[EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1  delme; 
sync )
0.04user 0.48system 6.52 (0m6.521s) elapsed 7.97%CPU
[EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1  delme; 
sync )
0.05user 0.61system 6.33 (0m6.333s) elapsed 10.42%CPU
[EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 | gzip - 
 delme; sync )
1.57user 0.32system 1.74 (0m1.749s) elapsed 100.00%CPU
[EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 | gzip - 
 delme; sync )
1.61user 0.18system 1.65 (0m1.652s) elapsed 100.00%CPU

Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) 
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-29 Thread Lennart Sorensen
On Mon, Oct 29, 2007 at 09:19:11PM +0100, Pavel Machek wrote:
 Tell it to your profesor ;-).

I don't have one.  I graduated 7 years ago.  I was just pointing holes
in the spec. :)

 Not neccessarily but yes, that would be nice, too.

If it doesn't it seems the compression feature is going to be rather
unpredictable and my optimization would be perfectly within spec and
make it pretty much useless.

 Yes. Typically for all zeros. It will be similar for
 highly-compressible data (pictures, timetables, )

That would make it tricky to say if you should ever skip compression due
to cpu load.  There is a chance cpu load would be better off by doing
the compression.

 [EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1  
 delme; sync )
 0.04user 0.48system 6.52 (0m6.521s) elapsed 7.97%CPU
 [EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1  
 delme; sync )
 0.05user 0.61system 6.33 (0m6.333s) elapsed 10.42%CPU
 [EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 | gzip 
 -  delme; sync )
 1.57user 0.32system 1.74 (0m1.749s) elapsed 100.00%CPU
 [EMAIL PROTECTED]:/data/tmp# time ( cat /dev/zero | head -c 1 | gzip 
 -  delme; sync )
 1.61user 0.18system 1.65 (0m1.652s) elapsed 100.00%CPU

--
Len Sorensen
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-29 Thread Lennart Sorensen
On Sun, Oct 28, 2007 at 06:07:07PM +, Pavel Machek wrote:
 Hard stuff:
 
 * network character device -- similar to nbd, but for char devices.
   either figure out how to forward ioctls(), or implement
   usb-over-network, or...
 
 * openMosix -- they seem to have userspace solution, but not GPLed.
 
 * compression for ext4. Its about time someone did it right. Special
   bonus if you can do it in a way that it does not slow down. If cpu
   is free, compress, if it is busy, just write it straight to disk.

So if I decide that the cpu is busy (because something is asking me to
write the cpu is clearly doing something and hence busy), then I can
skip compression and just write to disk.  So by that definition ext4
already does compression.  What a simple project. :)

Did you mean it ought to come back and do the compression later?

Is it possible that for some data compressing it and writing will take
less time than not compressing it and writing it to disk?

--
Len Sorensen
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-28 Thread Rafael J. Wysocki
On Sunday, 28 October 2007 19:07, Pavel Machek wrote:
> Hi!
> 
> > - Are large enough to qualify as a student project, luckily there is
> >   flexibility here since we get inquiries for anything from 6 week
> >   projects to 6 month projects.
> > 
> > If you have ideas on what projects would be useful, please add them
> > to this page (or email me):
> 
> Hard stuff:
> 
> * network character device -- similar to nbd, but for char devices.
>   either figure out how to forward ioctls(), or implement
>   usb-over-network, or...
> 
> * openMosix -- they seem to have userspace solution, but not GPLed.

The project is no longer being developed, AFAICS.

> * compression for ext4. Its about time someone did it right. Special
>   bonus if you can do it in a way that it does not slow down. If cpu
>   is free, compress, if it is busy, just write it straight to disk.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-28 Thread Pavel Machek
Hi!

> - Are large enough to qualify as a student project, luckily there is
>   flexibility here since we get inquiries for anything from 6 week
>   projects to 6 month projects.
> 
> If you have ideas on what projects would be useful, please add them
> to this page (or email me):

Hard stuff:

* network character device -- similar to nbd, but for char devices.
  either figure out how to forward ioctls(), or implement
  usb-over-network, or...

* openMosix -- they seem to have userspace solution, but not GPLed.

* compression for ext4. Its about time someone did it right. Special
  bonus if you can do it in a way that it does not slow down. If cpu
  is free, compress, if it is busy, just write it straight to disk.
Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) 
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-28 Thread Pavel Machek
Hi!

 - Are large enough to qualify as a student project, luckily there is
   flexibility here since we get inquiries for anything from 6 week
   projects to 6 month projects.
 
 If you have ideas on what projects would be useful, please add them
 to this page (or email me):

Hard stuff:

* network character device -- similar to nbd, but for char devices.
  either figure out how to forward ioctls(), or implement
  usb-over-network, or...

* openMosix -- they seem to have userspace solution, but not GPLed.

* compression for ext4. Its about time someone did it right. Special
  bonus if you can do it in a way that it does not slow down. If cpu
  is free, compress, if it is busy, just write it straight to disk.
Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) 
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-28 Thread Rafael J. Wysocki
On Sunday, 28 October 2007 19:07, Pavel Machek wrote:
 Hi!
 
  - Are large enough to qualify as a student project, luckily there is
flexibility here since we get inquiries for anything from 6 week
projects to 6 month projects.
  
  If you have ideas on what projects would be useful, please add them
  to this page (or email me):
 
 Hard stuff:
 
 * network character device -- similar to nbd, but for char devices.
   either figure out how to forward ioctls(), or implement
   usb-over-network, or...
 
 * openMosix -- they seem to have userspace solution, but not GPLed.

The project is no longer being developed, AFAICS.

 * compression for ext4. Its about time someone did it right. Special
   bonus if you can do it in a way that it does not slow down. If cpu
   is free, compress, if it is busy, just write it straight to disk.
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-18 Thread Toshiharu Harada

On 10/15/2007 8:01 AM, Rik van Riel wrote:
> The kernel newbies community often gets inquiries from CS students who
> need a project for their studies and would like to do something with
> the Linux kernel, but would also like their code to be useful to the
> community afterwards.
>
> In order to make it easier for them, I am trying to put together a
> page with projects that:
> - Are self contained enough that the students can implement the
>   project by themselves, since that is often a university requirement.
> - Are self contained enough that Linux could merge the code (maybe
>   with additional changes) after the student has been working on it
>   for a few months.
> - Are large enough to qualify as a student project, luckily there is
>   flexibility here since we get inquiries for anything from 6 week
>   projects to 6 month projects.
>
> If you have ideas on what projects would be useful, please add them
> to this page (or email me):
>
> http://kernelnewbies.org/KernelProjects

Well, I know something that might be interesting for kernel newbies
including students. So let me share it with you.
It's Ubuntu 7.04 based LiveCD with TOMOYO Linux kernel.

Directions:
1. visit the following URL and save ISO image
   http://tomoyo.sourceforge.jp/wiki-e/?TomoyoLive
2. burn CD/DVD and boot from the disc
   (or start up VM from the downloaded image)
3. open "TOOMYO Linux Policy Editor" icon on the gnome desktop
4. browse "domains" with cursor keys
   you can see how processes were created (great experience)
5. choose a domain and enter return key
   you can see the behavior of the selected "domain" (ACL mode)
6. enter return to step 5 (domain transition mode)
   (repeat 5-7 as you like, type 'r' to refresh screen)
7. enter q to quit the editpolicy program

As it's LiveCD like KNOPPIX, hard disks will not be
affected unless you mount them and operate with intention.
I mean, it's safe to play with.

What makes all of these possible is "TOMOYO Linux",
but you don't have to understand it. ;)
No policy definition, preparation, knowledge or hustle is
required.

If you are interested in TOMOYO Linux (just in case...),
please visit our Wiki page.
http://tomoyo.sourceforge.jp/wiki-e/?WhatIs

Cheers,
Toshiharu Harada
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-18 Thread Toshiharu Harada

On 10/15/2007 8:01 AM, Rik van Riel wrote:
 The kernel newbies community often gets inquiries from CS students who
 need a project for their studies and would like to do something with
 the Linux kernel, but would also like their code to be useful to the
 community afterwards.

 In order to make it easier for them, I am trying to put together a
 page with projects that:
 - Are self contained enough that the students can implement the
   project by themselves, since that is often a university requirement.
 - Are self contained enough that Linux could merge the code (maybe
   with additional changes) after the student has been working on it
   for a few months.
 - Are large enough to qualify as a student project, luckily there is
   flexibility here since we get inquiries for anything from 6 week
   projects to 6 month projects.

 If you have ideas on what projects would be useful, please add them
 to this page (or email me):

 http://kernelnewbies.org/KernelProjects

Well, I know something that might be interesting for kernel newbies
including students. So let me share it with you.
It's Ubuntu 7.04 based LiveCD with TOMOYO Linux kernel.

Directions:
1. visit the following URL and save ISO image
   http://tomoyo.sourceforge.jp/wiki-e/?TomoyoLive
2. burn CD/DVD and boot from the disc
   (or start up VM from the downloaded image)
3. open TOOMYO Linux Policy Editor icon on the gnome desktop
4. browse domains with cursor keys
   you can see how processes were created (great experience)
5. choose a domain and enter return key
   you can see the behavior of the selected domain (ACL mode)
6. enter return to step 5 (domain transition mode)
   (repeat 5-7 as you like, type 'r' to refresh screen)
7. enter q to quit the editpolicy program

As it's LiveCD like KNOPPIX, hard disks will not be
affected unless you mount them and operate with intention.
I mean, it's safe to play with.

What makes all of these possible is TOMOYO Linux,
but you don't have to understand it. ;)
No policy definition, preparation, knowledge or hustle is
required.

If you are interested in TOMOYO Linux (just in case...),
please visit our Wiki page.
http://tomoyo.sourceforge.jp/wiki-e/?WhatIs

Cheers,
Toshiharu Harada
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-17 Thread Mark Gross
On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
> The kernel newbies community often gets inquiries from CS students who
> need a project for their studies and would like to do something with
> the Linux kernel, but would also like their code to be useful to the
> community afterwards.
> 
> In order to make it easier for them, I am trying to put together a
> page with projects that:
> - Are self contained enough that the students can implement the
>   project by themselves, since that is often a university requirement.
> - Are self contained enough that Linux could merge the code (maybe
>   with additional changes) after the student has been working on it
>   for a few months.
> - Are large enough to qualify as a student project, luckily there is
>   flexibility here since we get inquiries for anything from 6 week
>   projects to 6 month projects.
> 
> If you have ideas on what projects would be useful, please add them
> to this page (or email me):
> 
> http://kernelnewbies.org/KernelProjects
>

How about a static code tool that will check for initialization races?
yesterday I found a lurker bug in some of my code that wouldn't have
been exposed had not tripped over it.  I wrote some infrastructure code
that initializes its lists and notification trees in late_init.  

Then I found  out that there was as client of my infrastructure calling
my register API at core_init time.  It didn't crash / fail noticeably,
but wasn't correct, because at that time I was using a static array. 
When I changed my code to use an array of pointers instead it went boom!
(FWIW I've fixed this issue for now...)

It made me feel uneasy how that issue got by un-noticed and I worry that
there could be more like it.  A tool to scan the code for boot up init
calls and check for any callers into any module for entry before the
module is fully initialized.  

--mgross
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-17 Thread Mark Gross
On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
 The kernel newbies community often gets inquiries from CS students who
 need a project for their studies and would like to do something with
 the Linux kernel, but would also like their code to be useful to the
 community afterwards.
 
 In order to make it easier for them, I am trying to put together a
 page with projects that:
 - Are self contained enough that the students can implement the
   project by themselves, since that is often a university requirement.
 - Are self contained enough that Linux could merge the code (maybe
   with additional changes) after the student has been working on it
   for a few months.
 - Are large enough to qualify as a student project, luckily there is
   flexibility here since we get inquiries for anything from 6 week
   projects to 6 month projects.
 
 If you have ideas on what projects would be useful, please add them
 to this page (or email me):
 
 http://kernelnewbies.org/KernelProjects


How about a static code tool that will check for initialization races?
yesterday I found a lurker bug in some of my code that wouldn't have
been exposed had not tripped over it.  I wrote some infrastructure code
that initializes its lists and notification trees in late_init.  

Then I found  out that there was as client of my infrastructure calling
my register API at core_init time.  It didn't crash / fail noticeably,
but wasn't correct, because at that time I was using a static array. 
When I changed my code to use an array of pointers instead it went boom!
(FWIW I've fixed this issue for now...)

It made me feel uneasy how that issue got by un-noticed and I worry that
there could be more like it.  A tool to scan the code for boot up init
calls and check for any callers into any module for entry before the
module is fully initialized.  

--mgross
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread david

On Tue, 16 Oct 2007, Rik van Riel wrote:


On Tue, 16 Oct 2007 22:09:04 +0200 (CEST)
Jan Engelhardt <[EMAIL PROTECTED]> wrote:

On Oct 16 2007 13:06, Mark Gross wrote:


base function:
Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
kernel.org tree and automatically create a .config with all the
drivers needed for the platform I'm building on.


Too easy. Since opensuse's udev loads most of the modules for your
hardware, all that would be needed is to transform the lsmod list of
modules plus the static options in /proc/config.gz (stuff like
psmouse) back into kconfig options ;-)


Well, at that point it does not know whether or not you
occasionally plug in an ipod or a digital camera.


you can ask the user to plugin all the different devices that they want to 
use when doing the config scan


bonus points if you have both the ability to go from nothing to a config 
_and_ take an existing config and add any additional drivers needed for 
the current hardware


David Lang


Going back from the lsmod output to all the right CONFIG
options is also not as trivial as it sounds, due to all
the dependencies there are.

This project sounds like it could be a great undergraduate
project, maybe built on top of Ketchup to automatically
fetch, configure, compile and install a working kernel :)

Are there any volunteers to write down the project
description on the kernelnewbies.org wiki?



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread david

On Tue, 16 Oct 2007, Jan Engelhardt wrote:


On Oct 16 2007 16:23, Rik van Riel wrote:


base function:
Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
kernel.org tree and automatically create a .config with all the
drivers needed for the platform I'm building on.


Too easy. Since opensuse's udev loads most of the modules for your
hardware, all that would be needed is to transform the lsmod list of
modules plus the static options in /proc/config.gz (stuff like
psmouse) back into kconfig options ;-)


Well, at that point it does not know whether or not you
occasionally plug in an ipod or a digital camera.


Which is why building an allmod kernel (or what the distros do)
is IMO the better solution.


if all you want is a config that will work you are right.

however if you want a good base for an optimized, minimal kernel it's not 
much help (other then possibly as a stepping stone to then examine all the 
modules that were loaded and document which ones are needed)


David Lang
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread Jan Engelhardt

On Oct 16 2007 16:23, Rik van Riel wrote:

>> >base function:
>> >Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
>> >kernel.org tree and automatically create a .config with all the
>> >drivers needed for the platform I'm building on.
>> 
>> Too easy. Since opensuse's udev loads most of the modules for your
>> hardware, all that would be needed is to transform the lsmod list of
>> modules plus the static options in /proc/config.gz (stuff like
>> psmouse) back into kconfig options ;-)
>
>Well, at that point it does not know whether or not you
>occasionally plug in an ipod or a digital camera.

Which is why building an allmod kernel (or what the distros do)
is IMO the better solution.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread Rik van Riel
On Tue, 16 Oct 2007 22:09:04 +0200 (CEST)
Jan Engelhardt <[EMAIL PROTECTED]> wrote:
> On Oct 16 2007 13:06, Mark Gross wrote:
> >
> >base function:
> >Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
> >kernel.org tree and automatically create a .config with all the
> >drivers needed for the platform I'm building on.
> 
> Too easy. Since opensuse's udev loads most of the modules for your
> hardware, all that would be needed is to transform the lsmod list of
> modules plus the static options in /proc/config.gz (stuff like
> psmouse) back into kconfig options ;-)

Well, at that point it does not know whether or not you
occasionally plug in an ipod or a digital camera.

Going back from the lsmod output to all the right CONFIG
options is also not as trivial as it sounds, due to all
the dependencies there are.

This project sounds like it could be a great undergraduate
project, maybe built on top of Ketchup to automatically
fetch, configure, compile and install a working kernel :)

Are there any volunteers to write down the project
description on the kernelnewbies.org wiki?

-- 
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread Mark Gross
On Mon, Oct 15, 2007 at 11:17:32PM +0400, Alexey Dobriyan wrote:
> On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
> > On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
> > > http://kernelnewbies.org/KernelProjects
> > 
> > Is there already a make config option that will do a good job at setting
> > a default .config file based on what is already running on a system?  
> > 
> > I get tiered of trimming down my .config for my laptop build so it takes
> > less than 30min to build a kernel.
> 
> Ehh? You do it once, then leave it aside or in /proc/config.gz, on new
> kernel copy it back, "make oldconfig", answer several questions and here
> we go.

yeah I know that.  Its a lot more than a few questions, and as we are
talking about a linear search for a fully tweaked .config where each
pass takes 30 min to know if things work this isn't how I want to spend
my time.

--mgross

> 
> > Bonus credit to additional "expert" options (like those powertop puts
> > out) for target uses, laptop, HPC, home file share, embedded targets
> > 
> > Oh, and lets make the expert configs easily extensible.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread Mark Gross
On Mon, Oct 15, 2007 at 09:54:42PM +0200, Giacomo Catenazzi wrote:
> Sam Ravnborg wrote:
> > On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
> >> On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
> >>> The kernel newbies community often gets inquiries from CS students who
> >>> need a project for their studies and would like to do something with
> >>> the Linux kernel, but would also like their code to be useful to the
> >>> community afterwards.
> >>>
> >>> In order to make it easier for them, I am trying to put together a
> >>> page with projects that:
> >>> - Are self contained enough that the students can implement the
> >>>   project by themselves, since that is often a university requirement.
> >>> - Are self contained enough that Linux could merge the code (maybe
> >>>   with additional changes) after the student has been working on it
> >>>   for a few months.
> >>> - Are large enough to qualify as a student project, luckily there is
> >>>   flexibility here since we get inquiries for anything from 6 week
> >>>   projects to 6 month projects.
> >>>
> >>> If you have ideas on what projects would be useful, please add them
> >>> to this page (or email me):
> >>>
> >>> http://kernelnewbies.org/KernelProjects
> >> Is there already a make config option that will do a good job at setting
> >> a default .config file based on what is already running on a system?  
> > I have discussed this briefly with Kay Sievers.
> > What udev can provide is the list of modules needed, so what the kernel
> > need to provide is a simple module to CONFIG option(s) converter + a base
> > config to start out with.
> > Nothing particular difficult but needs a few days work to do.
> 
> could you explain better what you need?  I think I've already such
> tools ;-)
>

base function:
Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
kernel.org tree and automatically create a .config with all the drivers
needed for the platform I'm building on.

expert configs for different applications:
laptop battery, vitalization, HPC, tiny, multi-media, testing

--mgross
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread Jan Engelhardt

On Oct 16 2007 13:06, Mark Gross wrote:
>
>base function:
>Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
>kernel.org tree and automatically create a .config with all the drivers
>needed for the platform I'm building on.

Too easy. Since opensuse's udev loads most of the modules for your hardware,
all that would be needed is to transform the lsmod list of modules plus
the static options in /proc/config.gz (stuff like psmouse) back
into kconfig options ;-)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread Mark Gross
On Mon, Oct 15, 2007 at 09:54:42PM +0200, Giacomo Catenazzi wrote:
 Sam Ravnborg wrote:
  On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
  On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
  The kernel newbies community often gets inquiries from CS students who
  need a project for their studies and would like to do something with
  the Linux kernel, but would also like their code to be useful to the
  community afterwards.
 
  In order to make it easier for them, I am trying to put together a
  page with projects that:
  - Are self contained enough that the students can implement the
project by themselves, since that is often a university requirement.
  - Are self contained enough that Linux could merge the code (maybe
with additional changes) after the student has been working on it
for a few months.
  - Are large enough to qualify as a student project, luckily there is
flexibility here since we get inquiries for anything from 6 week
projects to 6 month projects.
 
  If you have ideas on what projects would be useful, please add them
  to this page (or email me):
 
  http://kernelnewbies.org/KernelProjects
  Is there already a make config option that will do a good job at setting
  a default .config file based on what is already running on a system?  
  I have discussed this briefly with Kay Sievers.
  What udev can provide is the list of modules needed, so what the kernel
  need to provide is a simple module to CONFIG option(s) converter + a base
  config to start out with.
  Nothing particular difficult but needs a few days work to do.
 
 could you explain better what you need?  I think I've already such
 tools ;-)


base function:
Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
kernel.org tree and automatically create a .config with all the drivers
needed for the platform I'm building on.

expert configs for different applications:
laptop battery, vitalization, HPC, tiny, multi-media, testing

--mgross
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread Jan Engelhardt

On Oct 16 2007 13:06, Mark Gross wrote:

base function:
Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
kernel.org tree and automatically create a .config with all the drivers
needed for the platform I'm building on.

Too easy. Since opensuse's udev loads most of the modules for your hardware,
all that would be needed is to transform the lsmod list of modules plus
the static options in /proc/config.gz (stuff like psmouse) back
into kconfig options ;-)
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread Mark Gross
On Mon, Oct 15, 2007 at 11:17:32PM +0400, Alexey Dobriyan wrote:
 On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
  On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
   http://kernelnewbies.org/KernelProjects
  
  Is there already a make config option that will do a good job at setting
  a default .config file based on what is already running on a system?  
  
  I get tiered of trimming down my .config for my laptop build so it takes
  less than 30min to build a kernel.
 
 Ehh? You do it once, then leave it aside or in /proc/config.gz, on new
 kernel copy it back, make oldconfig, answer several questions and here
 we go.

yeah I know that.  Its a lot more than a few questions, and as we are
talking about a linear search for a fully tweaked .config where each
pass takes 30 min to know if things work this isn't how I want to spend
my time.

--mgross

 
  Bonus credit to additional expert options (like those powertop puts
  out) for target uses, laptop, HPC, home file share, embedded targets
  
  Oh, and lets make the expert configs easily extensible.
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread Rik van Riel
On Tue, 16 Oct 2007 22:09:04 +0200 (CEST)
Jan Engelhardt [EMAIL PROTECTED] wrote:
 On Oct 16 2007 13:06, Mark Gross wrote:
 
 base function:
 Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
 kernel.org tree and automatically create a .config with all the
 drivers needed for the platform I'm building on.
 
 Too easy. Since opensuse's udev loads most of the modules for your
 hardware, all that would be needed is to transform the lsmod list of
 modules plus the static options in /proc/config.gz (stuff like
 psmouse) back into kconfig options ;-)

Well, at that point it does not know whether or not you
occasionally plug in an ipod or a digital camera.

Going back from the lsmod output to all the right CONFIG
options is also not as trivial as it sounds, due to all
the dependencies there are.

This project sounds like it could be a great undergraduate
project, maybe built on top of Ketchup to automatically
fetch, configure, compile and install a working kernel :)

Are there any volunteers to write down the project
description on the kernelnewbies.org wiki?

-- 
Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it. - Brian W. Kernighan
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread Jan Engelhardt

On Oct 16 2007 16:23, Rik van Riel wrote:

 base function:
 Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
 kernel.org tree and automatically create a .config with all the
 drivers needed for the platform I'm building on.
 
 Too easy. Since opensuse's udev loads most of the modules for your
 hardware, all that would be needed is to transform the lsmod list of
 modules plus the static options in /proc/config.gz (stuff like
 psmouse) back into kconfig options ;-)

Well, at that point it does not know whether or not you
occasionally plug in an ipod or a digital camera.

Which is why building an allmod kernel (or what the distros do)
is IMO the better solution.
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread david

On Tue, 16 Oct 2007, Jan Engelhardt wrote:


On Oct 16 2007 16:23, Rik van Riel wrote:


base function:
Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
kernel.org tree and automatically create a .config with all the
drivers needed for the platform I'm building on.


Too easy. Since opensuse's udev loads most of the modules for your
hardware, all that would be needed is to transform the lsmod list of
modules plus the static options in /proc/config.gz (stuff like
psmouse) back into kconfig options ;-)


Well, at that point it does not know whether or not you
occasionally plug in an ipod or a digital camera.


Which is why building an allmod kernel (or what the distros do)
is IMO the better solution.


if all you want is a config that will work you are right.

however if you want a good base for an optimized, minimal kernel it's not 
much help (other then possibly as a stepping stone to then examine all the 
modules that were loaded and document which ones are needed)


David Lang
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-16 Thread david

On Tue, 16 Oct 2007, Rik van Riel wrote:


On Tue, 16 Oct 2007 22:09:04 +0200 (CEST)
Jan Engelhardt [EMAIL PROTECTED] wrote:

On Oct 16 2007 13:06, Mark Gross wrote:


base function:
Starting from a stock distro (FC, Ubuntu, OpenSuSE...) and put down a
kernel.org tree and automatically create a .config with all the
drivers needed for the platform I'm building on.


Too easy. Since opensuse's udev loads most of the modules for your
hardware, all that would be needed is to transform the lsmod list of
modules plus the static options in /proc/config.gz (stuff like
psmouse) back into kconfig options ;-)


Well, at that point it does not know whether or not you
occasionally plug in an ipod or a digital camera.


you can ask the user to plugin all the different devices that they want to 
use when doing the config scan


bonus points if you have both the ability to go from nothing to a config 
_and_ take an existing config and add any additional drivers needed for 
the current hardware


David Lang


Going back from the lsmod output to all the right CONFIG
options is also not as trivial as it sounds, due to all
the dependencies there are.

This project sounds like it could be a great undergraduate
project, maybe built on top of Ketchup to automatically
fetch, configure, compile and install a working kernel :)

Are there any volunteers to write down the project
description on the kernelnewbies.org wiki?



-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread david

On Mon, 15 Oct 2007, Zan Lynx wrote:


On Sun, 2007-10-14 at 19:01 -0400, Rik van Riel wrote:

The kernel newbies community often gets inquiries from CS students who
need a project for their studies and would like to do something with
the Linux kernel, but would also like their code to be useful to the
community afterwards.

In order to make it easier for them, I am trying to put together a
page with projects that:
- Are self contained enough that the students can implement the
  project by themselves, since that is often a university requirement.
- Are self contained enough that Linux could merge the code (maybe
  with additional changes) after the student has been working on it
  for a few months.
- Are large enough to qualify as a student project, luckily there is
  flexibility here since we get inquiries for anything from 6 week
  projects to 6 month projects.

If you have ideas on what projects would be useful, please add them
to this page (or email me):

http://kernelnewbies.org/KernelProjects


How about this in the Device Mapper raid-1/mirror code?
/* FIXME: add read balancing */

That comment has been in there for many releases.  I've wanted read
balancing for several servers and had all sorts of ideas about it, like
adding functions to the underlying device queues to return a "queuing
cost" to determine which is the best queue to add the read request.  I
think that could work better for queues like CFQ than the MD
closest-head.

An implementation would also need to be benchmarked against the MD
raid-1.

Along with the time to submit it to LKML, get it reviewed and polish it
up, it might make a good student project.


another couple of raid enhancements would be:

1. teach the system that a raid456 stripe is handled most efficiantly if 
treated as a single block of data


by this I mean that if you read one block from the stripe the system reads 
the entire stripe, so it should take this into account when doing 
read-ahead and not always throw away most of the data it read becouse it's 
outside the current readahead window (if nothing else, look at putting it 
on the tail of the LRU list instead of just forgetting it)


if you write one block of the stripe the system must read the stripe, then 
update two blocks of the stripe (the data block and the parity block), but 
if you are going to write the entire stripe out you can ignore whatever's 
there and just calculate the parity block from the data you are writing. 
this should make writing to a raid456 stripe as fast as writing to a raid0 
stripe (well, almost, you have one more block to write).



2. not directly a kernel project, create userspace tools that make 
managing raid and partitioning on linux as easy as the zfs tools



3. there is currently the ability to grow a raid56 array by adding a disk, 
but there is not the ability to take a raid5 array, add a disk and make 
the result a raid6 array.


David Lang
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread david

On Mon, 15 Oct 2007, Mark Gross wrote:


On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:

The kernel newbies community often gets inquiries from CS students who
need a project for their studies and would like to do something with
the Linux kernel, but would also like their code to be useful to the
community afterwards.

In order to make it easier for them, I am trying to put together a
page with projects that:
- Are self contained enough that the students can implement the
  project by themselves, since that is often a university requirement.
- Are self contained enough that Linux could merge the code (maybe
  with additional changes) after the student has been working on it
  for a few months.
- Are large enough to qualify as a student project, luckily there is
  flexibility here since we get inquiries for anything from 6 week
  projects to 6 month projects.

If you have ideas on what projects would be useful, please add them
to this page (or email me):

http://kernelnewbies.org/KernelProjects


Is there already a make config option that will do a good job at setting
a default .config file based on what is already running on a system?

I get tiered of trimming down my .config for my laptop build so it takes
less than 30min to build a kernel.

Bonus credit to additional "expert" options (like those powertop puts
out) for target uses, laptop, HPC, home file share, embedded targets

Oh, and lets make the expert configs easily extensible.


another config thing that would be nice would be to take something like 
Rob Landley's miniconfig tool and make it work well enough to be 
integrated (it creates a version of .config that only contains the things 
that need to be set, not everything that's at a default that doesn't make 
any difference)


David Lang
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Folkert van Heusden
> > > http://kernelnewbies.org/KernelProjects
> > 
> > Is there already a make config option that will do a good job at setting
> > a default .config file based on what is already running on a system?  
> > 
> > I get tiered of trimming down my .config for my laptop build so it takes
> > less than 30min to build a kernel.
> 
> Ehh? You do it once, then leave it aside or in /proc/config.gz, on new
> kernel copy it back, "make oldconfig", answer several questions and here
> we go.

Ah yes, but then you buy a new system to which the old config does not
apply.


Folkert van Heusden

-- 
www.vanheusden.com/multitail - win een vlaai van multivlaai! zorg
ervoor dat multitail opgenomen wordt in Fedora Core, AIX, Solaris of
HP/UX en win een vlaai naar keuze
--
Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Giacomo Catenazzi
Sam Ravnborg wrote:
> On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
>> On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
>>> The kernel newbies community often gets inquiries from CS students who
>>> need a project for their studies and would like to do something with
>>> the Linux kernel, but would also like their code to be useful to the
>>> community afterwards.
>>>
>>> In order to make it easier for them, I am trying to put together a
>>> page with projects that:
>>> - Are self contained enough that the students can implement the
>>>   project by themselves, since that is often a university requirement.
>>> - Are self contained enough that Linux could merge the code (maybe
>>>   with additional changes) after the student has been working on it
>>>   for a few months.
>>> - Are large enough to qualify as a student project, luckily there is
>>>   flexibility here since we get inquiries for anything from 6 week
>>>   projects to 6 month projects.
>>>
>>> If you have ideas on what projects would be useful, please add them
>>> to this page (or email me):
>>>
>>> http://kernelnewbies.org/KernelProjects
>> Is there already a make config option that will do a good job at setting
>> a default .config file based on what is already running on a system?  
> I have discussed this briefly with Kay Sievers.
> What udev can provide is the list of modules needed, so what the kernel
> need to provide is a simple module to CONFIG option(s) converter + a base
> config to start out with.
> Nothing particular difficult but needs a few days work to do.

could you explain better what you need?  I think I've already such
tools ;-)

ciao
cate
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Alexey Dobriyan
On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
> On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
> > http://kernelnewbies.org/KernelProjects
> 
> Is there already a make config option that will do a good job at setting
> a default .config file based on what is already running on a system?  
> 
> I get tiered of trimming down my .config for my laptop build so it takes
> less than 30min to build a kernel.

Ehh? You do it once, then leave it aside or in /proc/config.gz, on new
kernel copy it back, "make oldconfig", answer several questions and here
we go.

> Bonus credit to additional "expert" options (like those powertop puts
> out) for target uses, laptop, HPC, home file share, embedded targets
> 
> Oh, and lets make the expert configs easily extensible.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Mark Gross
On Mon, Oct 15, 2007 at 08:30:17PM +0200, Sam Ravnborg wrote:
> On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
> > On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
> > > The kernel newbies community often gets inquiries from CS students who
> > > need a project for their studies and would like to do something with
> > > the Linux kernel, but would also like their code to be useful to the
> > > community afterwards.
> > > 
> > > In order to make it easier for them, I am trying to put together a
> > > page with projects that:
> > > - Are self contained enough that the students can implement the
> > >   project by themselves, since that is often a university requirement.
> > > - Are self contained enough that Linux could merge the code (maybe
> > >   with additional changes) after the student has been working on it
> > >   for a few months.
> > > - Are large enough to qualify as a student project, luckily there is
> > >   flexibility here since we get inquiries for anything from 6 week
> > >   projects to 6 month projects.
> > > 
> > > If you have ideas on what projects would be useful, please add them
> > > to this page (or email me):
> > > 
> > > http://kernelnewbies.org/KernelProjects
> > 
> > Is there already a make config option that will do a good job at setting
> > a default .config file based on what is already running on a system?  
> I have discussed this briefly with Kay Sievers.
> What udev can provide is the list of modules needed, so what the kernel
> need to provide is a simple module to CONFIG option(s) converter + a base
> config to start out with.
> Nothing particular difficult but needs a few days work to do.
> 

that would be cool.

--mgross
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Sam Ravnborg
On Mon, Oct 15, 2007 at 11:10:40AM -0400, Rik van Riel wrote:
> On Mon, 15 Oct 2007 16:23:52 +0200
> Sam Ravnborg <[EMAIL PROTECTED]> wrote:
> 
> > > If you have ideas on what projects would be useful, please add them
> > > to this page (or email me):
> > > 
> > > http://kernelnewbies.org/KernelProjects
> > 
> > In the kernel build area a few possible projects exists.
> 
> Thank you Sam, I have added your project ideas to the page.

Thanks for adding these.

Sam
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Sam Ravnborg
On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
> On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
> > The kernel newbies community often gets inquiries from CS students who
> > need a project for their studies and would like to do something with
> > the Linux kernel, but would also like their code to be useful to the
> > community afterwards.
> > 
> > In order to make it easier for them, I am trying to put together a
> > page with projects that:
> > - Are self contained enough that the students can implement the
> >   project by themselves, since that is often a university requirement.
> > - Are self contained enough that Linux could merge the code (maybe
> >   with additional changes) after the student has been working on it
> >   for a few months.
> > - Are large enough to qualify as a student project, luckily there is
> >   flexibility here since we get inquiries for anything from 6 week
> >   projects to 6 month projects.
> > 
> > If you have ideas on what projects would be useful, please add them
> > to this page (or email me):
> > 
> > http://kernelnewbies.org/KernelProjects
> 
> Is there already a make config option that will do a good job at setting
> a default .config file based on what is already running on a system?  
I have discussed this briefly with Kay Sievers.
What udev can provide is the list of modules needed, so what the kernel
need to provide is a simple module to CONFIG option(s) converter + a base
config to start out with.
Nothing particular difficult but needs a few days work to do.

Sam
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Sam Ravnborg
On Mon, Oct 15, 2007 at 06:31:54PM +0200, Philippe Elie wrote:
> > Increase speed for a build with no updates
> > ==
> > On a resonably fast machine with a decent config it takes
> > roughly 10 seconds to do a make where nothing is updated.
> > Generating one single Makefile is assumed to speed up things
> > and will in addition allow a simpler syntax as what is used today
> > for some of the uglier constructs.
> > 
> > Contact: Sam Ravnborg <[EMAIL PROTECTED]>
> > Difficulty: 5
> > Language: Perl or C
> 
> Isn't make -j 2 or more implemented by running multiple make in sub-dirs ?
> Parallel make is more and more used even on cheap hardware.

The kernel build system supports parallel make and I guess all
kernel developers use it. People tell me that a 32 way machine is
quite good for kernel compilation.

The bottleneck is that we spawn so many make instances and each have
to read all the same makefiles and stat in total a zillion files
for a simple kernel build.

With a single Makefile we can run a single instance make where
we read all files only once and stat the same file only once.

Sam
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread J. Bruce Fields
On Mon, Oct 15, 2007 at 03:30:41PM -0200, Guilherme Amadio wrote:
>  I read the messages about the company list and now this CS projects list and
>  I was wondering if is there any similar list of labs/universities that host
>  PhD projects related to the Linux kernel. I am thinking about switching from
>  physics to CS and it would be really cool to work with the kernel.

You might take a look at proceedings for conferences with recent
linux-related papers (linuxsymposium.org, usenix.org, linux.org.au, ?)
and look for urls and presenters with .edu addresses.

--b.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Guilherme Amadio
 Hello,

 I read the messages about the company list and now this CS projects list and
 I was wondering if is there any similar list of labs/universities that host
 PhD projects related to the Linux kernel. I am thinking about switching from
 physics to CS and it would be really cool to work with the kernel.

 Thanks in advance,

 Guilherme

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Rik van Riel
On Mon, 15 Oct 2007 11:10:32 -0600
Zan Lynx <[EMAIL PROTECTED]> wrote:

> > http://kernelnewbies.org/KernelProjects
> 
> How about this in the Device Mapper raid-1/mirror code?
>   /* FIXME: add read balancing */
> 
> That comment has been in there for many releases.  I've wanted read
> balancing for several servers and had all sorts of ideas about it,

I've written down the basic description:

http://kernelnewbies.org/KernelProjects/Raid1ReadBalancing

Could you add any ideas that you have to the page?
It is a wiki, so anybody can edit the site (after
creating an account).

-- 
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Rik van Riel
On Mon, 15 Oct 2007 18:40:34 +0800
WANG Cong <[EMAIL PROTECTED]> wrote:

> >http://kernelnewbies.org/KernelProjects
> 
> Thanks very much, Rik. I need this eagerly.
> 
> I want to find a kernel project that can both be my graduation thesis
> and contribute to the Linux kernel community. I read that page and
> think your project--Swapout Clustering is interesting for me.
> Is it alright for me to work on it? And can you give some help?

You would be the third student to take on that project
simultaneously.  That is not a problem for me (on the
contrary, it increases the chances of one codebase being
likeable to Linus), but it does decrease the chances of
your patch being the one to make it upstream.

Still, it should be a fun project to implement and
benchmark, so go ahead if you want.

-- 
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Mark Gross
On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
> The kernel newbies community often gets inquiries from CS students who
> need a project for their studies and would like to do something with
> the Linux kernel, but would also like their code to be useful to the
> community afterwards.
> 
> In order to make it easier for them, I am trying to put together a
> page with projects that:
> - Are self contained enough that the students can implement the
>   project by themselves, since that is often a university requirement.
> - Are self contained enough that Linux could merge the code (maybe
>   with additional changes) after the student has been working on it
>   for a few months.
> - Are large enough to qualify as a student project, luckily there is
>   flexibility here since we get inquiries for anything from 6 week
>   projects to 6 month projects.
> 
> If you have ideas on what projects would be useful, please add them
> to this page (or email me):
> 
> http://kernelnewbies.org/KernelProjects

Is there already a make config option that will do a good job at setting
a default .config file based on what is already running on a system?  

I get tiered of trimming down my .config for my laptop build so it takes
less than 30min to build a kernel.

Bonus credit to additional "expert" options (like those powertop puts
out) for target uses, laptop, HPC, home file share, embedded targets

Oh, and lets make the expert configs easily extensible.


--mgross


> 
> thanks,
> 
> Rik
> -- 
> "Debugging is twice as hard as writing the code in the first place.
> Therefore, if you write the code as cleverly as possible, you are,
> by definition, not smart enough to debug it." - Brian W. Kernighan
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [EMAIL PROTECTED]
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Zan Lynx
On Sun, 2007-10-14 at 19:01 -0400, Rik van Riel wrote:
> The kernel newbies community often gets inquiries from CS students who
> need a project for their studies and would like to do something with
> the Linux kernel, but would also like their code to be useful to the
> community afterwards.
> 
> In order to make it easier for them, I am trying to put together a
> page with projects that:
> - Are self contained enough that the students can implement the
>   project by themselves, since that is often a university requirement.
> - Are self contained enough that Linux could merge the code (maybe
>   with additional changes) after the student has been working on it
>   for a few months.
> - Are large enough to qualify as a student project, luckily there is
>   flexibility here since we get inquiries for anything from 6 week
>   projects to 6 month projects.
> 
> If you have ideas on what projects would be useful, please add them
> to this page (or email me):
> 
> http://kernelnewbies.org/KernelProjects

How about this in the Device Mapper raid-1/mirror code?
/* FIXME: add read balancing */

That comment has been in there for many releases.  I've wanted read
balancing for several servers and had all sorts of ideas about it, like
adding functions to the underlying device queues to return a "queuing
cost" to determine which is the best queue to add the read request.  I
think that could work better for queues like CFQ than the MD
closest-head.

An implementation would also need to be benchmarked against the MD
raid-1.

Along with the time to submit it to LKML, get it reviewed and polish it
up, it might make a good student project.
-- 
Zan Lynx <[EMAIL PROTECTED]>


signature.asc
Description: This is a digitally signed message part


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Doug Whitesell (LKML)


On Oct 14, 2007, at 4:01 PM, Rik van Riel wrote:


The kernel newbies community often gets inquiries from CS students who
need a project for their studies and would like to do something with
the Linux kernel, but would also like their code to be useful to the
community afterwards.

In order to make it easier for them, I am trying to put together a
page with projects that:
- Are self contained enough that the students can implement the
  project by themselves, since that is often a university requirement.
- Are self contained enough that Linux could merge the code (maybe
  with additional changes) after the student has been working on it
  for a few months.
- Are large enough to qualify as a student project, luckily there is
  flexibility here since we get inquiries for anything from 6 week
  projects to 6 month projects.

If you have ideas on what projects would be useful, please add them
to this page (or email me):

http://kernelnewbies.org/KernelProjects


I'm also quite interested in what compsci students can do for the  
kernel project. I'm currently doing a little embedded development and  
research at school, but I and a few others would jump at the chance  
to work on the kernel (besides finding duplicate problems that the  
x86 merge is already taking care of, of course. ;)


Also (as an aside), we're looking at redoing our operating systems  
curriculum out here at school...anyone aware of (relatively good) OS  
curricula? (time scope: one semester.)


regards/thanks,
--
Doug Whitesell
CSU Channel Islands - Computer Science
"Unprecedented performance: nothing we had has ever worked like this  
before..."

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Xavier Bestel
On Mon, 2007-10-15 at 18:36 +0200, Philippe Elie wrote:
> > > Increase speed for a build with no updates
> > > ==
> > > On a resonably fast machine with a decent config it takes
> > > roughly 10 seconds to do a make where nothing is updated.
> > > Generating one single Makefile is assumed to speed up things
> > > and will in addition allow a simpler syntax as what is used today
> > > for some of the uglier constructs.
> > > 
> > > Contact: Sam Ravnborg <[EMAIL PROTECTED]>
> > > Difficulty: 5
> > > Language: Perl or C
> > 
> > Isn't make -j 2 or more implemented by running multiple make in sub-dirs ?
> > Parallel make is more and more used even on cheap hardware.
> 
> Errm, I misread what you said, it can be a single Makefile in each sub-dirs

make -j works fine with an unique Makefile, if that's the question.

Xav


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Jan Engelhardt

On Oct 15 2007 18:36, Philippe Elie wrote:
>> 
>> Isn't make -j 2 or more implemented by running multiple make in sub-dirs ?
>> Parallel make is more and more used even on cheap hardware.
>
>Errm, I misread what you said, it can be a single Makefile in each sub-dirs

Even now, make -j8 really pays off on bigiron AMD.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Philippe Elie
On Mon, 15 Oct 2007 at 18:31 +, Philippe Elie wrote:

> On Mon, 15 Oct 2007 at 16:23 +, Sam Ravnborg wrote:
> 
> > Hi Rik.
> > 
> > On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
> > > The kernel newbies community often gets inquiries from CS students who
> > > need a project for their studies and would like to do something with
> > > the Linux kernel, but would also like their code to be useful to the
> > > community afterwards.
> > > 
> 
> ... 
> 
> > Increase speed for a build with no updates
> > ==
> > On a resonably fast machine with a decent config it takes
> > roughly 10 seconds to do a make where nothing is updated.
> > Generating one single Makefile is assumed to speed up things
> > and will in addition allow a simpler syntax as what is used today
> > for some of the uglier constructs.
> > 
> > Contact: Sam Ravnborg <[EMAIL PROTECTED]>
> > Difficulty: 5
> > Language: Perl or C
> 
> Isn't make -j 2 or more implemented by running multiple make in sub-dirs ?
> Parallel make is more and more used even on cheap hardware.

Errm, I misread what you said, it can be a single Makefile in each sub-dirs

> 
> -- 
> Phe
> 

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Philippe Elie
On Mon, 15 Oct 2007 at 16:23 +, Sam Ravnborg wrote:

> Hi Rik.
> 
> On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
> > The kernel newbies community often gets inquiries from CS students who
> > need a project for their studies and would like to do something with
> > the Linux kernel, but would also like their code to be useful to the
> > community afterwards.
> > 

... 

> Increase speed for a build with no updates
> ==
> On a resonably fast machine with a decent config it takes
> roughly 10 seconds to do a make where nothing is updated.
> Generating one single Makefile is assumed to speed up things
> and will in addition allow a simpler syntax as what is used today
> for some of the uglier constructs.
> 
> Contact: Sam Ravnborg <[EMAIL PROTECTED]>
> Difficulty: 5
> Language: Perl or C

Isn't make -j 2 or more implemented by running multiple make in sub-dirs ?
Parallel make is more and more used even on cheap hardware.

-- 
Phe

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Jörn Engel
On Sun, 14 October 2007 19:01:28 -0400, Rik van Riel wrote:
> 
> If you have ideas on what projects would be useful, please add them
> to this page (or email me):

Maybe this:

Allow removal of select from Kconfig files

Difficulty: 4

Many config options depend on other options is unrelated submenus.  As a
result, people have complained about not being able to select the
desired option because they finding all dependencies is too complicated.
Select solves this problem and creates a near-identical new one.  Now it
is just as hard to turn some options _off_ as it was before to turn
others _on_.

The solution would be to have smarter tools that give the user
information roughly like this:
  [ ] CONFIG_FOO
  If you enable this option, you will also enable CONFIG_BAR.
Or :
  [x] CONFIG_BAR
  If you disable this option you will also disable CONFIG_FOO
  and CONFIG_FOO2.

Difficulty is somewhat increased by the number of tools that require
such functionality.  Support for xconfig and menuconfig appears to have
priority as those users have a harder time grepping the kernel.

Jörn

-- 
There is no worse hell than that provided by the regrets
for wasted opportunities.
-- Andre-Louis Moreau in Scarabouche
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Rik van Riel
On Mon, 15 Oct 2007 16:23:52 +0200
Sam Ravnborg <[EMAIL PROTECTED]> wrote:

> > If you have ideas on what projects would be useful, please add them
> > to this page (or email me):
> > 
> > http://kernelnewbies.org/KernelProjects
> 
> In the kernel build area a few possible projects exists.

Thank you Sam, I have added your project ideas to the page.

-- 
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Sam Ravnborg
Hi Rik.

On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
> The kernel newbies community often gets inquiries from CS students who
> need a project for their studies and would like to do something with
> the Linux kernel, but would also like their code to be useful to the
> community afterwards.
> 
> In order to make it easier for them, I am trying to put together a
> page with projects that:
> - Are self contained enough that the students can implement the
>   project by themselves, since that is often a university requirement.
> - Are self contained enough that Linux could merge the code (maybe
>   with additional changes) after the student has been working on it
>   for a few months.
> - Are large enough to qualify as a student project, luckily there is
>   flexibility here since we get inquiries for anything from 6 week
>   projects to 6 month projects.
> 
> If you have ideas on what projects would be useful, please add them
> to this page (or email me):
> 
> http://kernelnewbies.org/KernelProjects

In the kernel build area a few possible projects exists.

Increase speed for a build with no updates
==
On a resonably fast machine with a decent config it takes
roughly 10 seconds to do a make where nothing is updated.
Generating one single Makefile is assumed to speed up things
and will in addition allow a simpler syntax as what is used today
for some of the uglier constructs.

Contact: Sam Ravnborg <[EMAIL PROTECTED]>
Difficulty: 5
Language: Perl or C


Increase speed for a build wich updates a single file
=
We often edit a single file and then do a build.
And the result is that we spend 80% of the time linking
the kernel.
So an obvious improvement for the kernel community would
be to improve the speed of the linker (and decrease memory footprint).

Contact: ?
Difficulty: ?
Language: C

Update menuconfig to a modern ncurses look
===
htop, aptitude, tig and other ncurses based programs has
a more modern and effective look than current menuconfig.
Rip out all the lxdialog stuff and replace it with a ncurses
based frontend that looks better and has more functionality.

Contact: Sam Ravnborg <[EMAIL PROTECTED]>
Difficulty: 5
Language: C


They are independent but challenging and would be very much appreciated
by the kernel community.

I could come up with more projects but these are the ones that are most
straightforward to start with.

Sam
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread WANG Cong
On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
>The kernel newbies community often gets inquiries from CS students who
>need a project for their studies and would like to do something with
>the Linux kernel, but would also like their code to be useful to the
>community afterwards.
>
>In order to make it easier for them, I am trying to put together a
>page with projects that:
>- Are self contained enough that the students can implement the
>  project by themselves, since that is often a university requirement.
>- Are self contained enough that Linux could merge the code (maybe
>  with additional changes) after the student has been working on it
>  for a few months.
>- Are large enough to qualify as a student project, luckily there is
>  flexibility here since we get inquiries for anything from 6 week
>  projects to 6 month projects.
>
>If you have ideas on what projects would be useful, please add them
>to this page (or email me):
>
>http://kernelnewbies.org/KernelProjects

Thanks very much, Rik. I need this eagerly.

I want to find a kernel project that can both be my graduation thesis
and contribute to the Linux kernel community. I read that page and
think your project--Swapout Clustering is interesting for me.
Is it alright for me to work on it? And can you give some help?

Thanks!

-- 
May the Source Be With You.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread WANG Cong
On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
The kernel newbies community often gets inquiries from CS students who
need a project for their studies and would like to do something with
the Linux kernel, but would also like their code to be useful to the
community afterwards.

In order to make it easier for them, I am trying to put together a
page with projects that:
- Are self contained enough that the students can implement the
  project by themselves, since that is often a university requirement.
- Are self contained enough that Linux could merge the code (maybe
  with additional changes) after the student has been working on it
  for a few months.
- Are large enough to qualify as a student project, luckily there is
  flexibility here since we get inquiries for anything from 6 week
  projects to 6 month projects.

If you have ideas on what projects would be useful, please add them
to this page (or email me):

http://kernelnewbies.org/KernelProjects

Thanks very much, Rik. I need this eagerly.

I want to find a kernel project that can both be my graduation thesis
and contribute to the Linux kernel community. I read that page and
think your project--Swapout Clustering is interesting for me.
Is it alright for me to work on it? And can you give some help?

Thanks!

-- 
May the Source Be With You.
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Sam Ravnborg
Hi Rik.

On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
 The kernel newbies community often gets inquiries from CS students who
 need a project for their studies and would like to do something with
 the Linux kernel, but would also like their code to be useful to the
 community afterwards.
 
 In order to make it easier for them, I am trying to put together a
 page with projects that:
 - Are self contained enough that the students can implement the
   project by themselves, since that is often a university requirement.
 - Are self contained enough that Linux could merge the code (maybe
   with additional changes) after the student has been working on it
   for a few months.
 - Are large enough to qualify as a student project, luckily there is
   flexibility here since we get inquiries for anything from 6 week
   projects to 6 month projects.
 
 If you have ideas on what projects would be useful, please add them
 to this page (or email me):
 
 http://kernelnewbies.org/KernelProjects

In the kernel build area a few possible projects exists.

Increase speed for a build with no updates
==
On a resonably fast machine with a decent config it takes
roughly 10 seconds to do a make where nothing is updated.
Generating one single Makefile is assumed to speed up things
and will in addition allow a simpler syntax as what is used today
for some of the uglier constructs.

Contact: Sam Ravnborg [EMAIL PROTECTED]
Difficulty: 5
Language: Perl or C


Increase speed for a build wich updates a single file
=
We often edit a single file and then do a build.
And the result is that we spend 80% of the time linking
the kernel.
So an obvious improvement for the kernel community would
be to improve the speed of the linker (and decrease memory footprint).

Contact: ?
Difficulty: ?
Language: C

Update menuconfig to a modern ncurses lookfeel
===
htop, aptitude, tig and other ncurses based programs has
a more modern and effective lookfeel than current menuconfig.
Rip out all the lxdialog stuff and replace it with a ncurses
based frontend that looks better and has more functionality.

Contact: Sam Ravnborg [EMAIL PROTECTED]
Difficulty: 5
Language: C


They are independent but challenging and would be very much appreciated
by the kernel community.

I could come up with more projects but these are the ones that are most
straightforward to start with.

Sam
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Rik van Riel
On Mon, 15 Oct 2007 16:23:52 +0200
Sam Ravnborg [EMAIL PROTECTED] wrote:

  If you have ideas on what projects would be useful, please add them
  to this page (or email me):
  
  http://kernelnewbies.org/KernelProjects
 
 In the kernel build area a few possible projects exists.

Thank you Sam, I have added your project ideas to the page.

-- 
Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it. - Brian W. Kernighan
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Jörn Engel
On Sun, 14 October 2007 19:01:28 -0400, Rik van Riel wrote:
 
 If you have ideas on what projects would be useful, please add them
 to this page (or email me):

Maybe this:

Allow removal of select from Kconfig files

Difficulty: 4

Many config options depend on other options is unrelated submenus.  As a
result, people have complained about not being able to select the
desired option because they finding all dependencies is too complicated.
Select solves this problem and creates a near-identical new one.  Now it
is just as hard to turn some options _off_ as it was before to turn
others _on_.

The solution would be to have smarter tools that give the user
information roughly like this:
  [ ] CONFIG_FOO
  If you enable this option, you will also enable CONFIG_BAR.
Or :
  [x] CONFIG_BAR
  If you disable this option you will also disable CONFIG_FOO
  and CONFIG_FOO2.

Difficulty is somewhat increased by the number of tools that require
such functionality.  Support for xconfig and menuconfig appears to have
priority as those users have a harder time grepping the kernel.

Jörn

-- 
There is no worse hell than that provided by the regrets
for wasted opportunities.
-- Andre-Louis Moreau in Scarabouche
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Philippe Elie
On Mon, 15 Oct 2007 at 16:23 +, Sam Ravnborg wrote:

 Hi Rik.
 
 On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
  The kernel newbies community often gets inquiries from CS students who
  need a project for their studies and would like to do something with
  the Linux kernel, but would also like their code to be useful to the
  community afterwards.
  

... 

 Increase speed for a build with no updates
 ==
 On a resonably fast machine with a decent config it takes
 roughly 10 seconds to do a make where nothing is updated.
 Generating one single Makefile is assumed to speed up things
 and will in addition allow a simpler syntax as what is used today
 for some of the uglier constructs.
 
 Contact: Sam Ravnborg [EMAIL PROTECTED]
 Difficulty: 5
 Language: Perl or C

Isn't make -j 2 or more implemented by running multiple make in sub-dirs ?
Parallel make is more and more used even on cheap hardware.

-- 
Phe

-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Philippe Elie
On Mon, 15 Oct 2007 at 18:31 +, Philippe Elie wrote:

 On Mon, 15 Oct 2007 at 16:23 +, Sam Ravnborg wrote:
 
  Hi Rik.
  
  On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
   The kernel newbies community often gets inquiries from CS students who
   need a project for their studies and would like to do something with
   the Linux kernel, but would also like their code to be useful to the
   community afterwards.
   
 
 ... 
 
  Increase speed for a build with no updates
  ==
  On a resonably fast machine with a decent config it takes
  roughly 10 seconds to do a make where nothing is updated.
  Generating one single Makefile is assumed to speed up things
  and will in addition allow a simpler syntax as what is used today
  for some of the uglier constructs.
  
  Contact: Sam Ravnborg [EMAIL PROTECTED]
  Difficulty: 5
  Language: Perl or C
 
 Isn't make -j 2 or more implemented by running multiple make in sub-dirs ?
 Parallel make is more and more used even on cheap hardware.

Errm, I misread what you said, it can be a single Makefile in each sub-dirs

 
 -- 
 Phe
 

-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Jan Engelhardt

On Oct 15 2007 18:36, Philippe Elie wrote:
 
 Isn't make -j 2 or more implemented by running multiple make in sub-dirs ?
 Parallel make is more and more used even on cheap hardware.

Errm, I misread what you said, it can be a single Makefile in each sub-dirs

Even now, make -j8 really pays off on bigiron AMD.
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Xavier Bestel
On Mon, 2007-10-15 at 18:36 +0200, Philippe Elie wrote:
   Increase speed for a build with no updates
   ==
   On a resonably fast machine with a decent config it takes
   roughly 10 seconds to do a make where nothing is updated.
   Generating one single Makefile is assumed to speed up things
   and will in addition allow a simpler syntax as what is used today
   for some of the uglier constructs.
   
   Contact: Sam Ravnborg [EMAIL PROTECTED]
   Difficulty: 5
   Language: Perl or C
  
  Isn't make -j 2 or more implemented by running multiple make in sub-dirs ?
  Parallel make is more and more used even on cheap hardware.
 
 Errm, I misread what you said, it can be a single Makefile in each sub-dirs

make -j works fine with an unique Makefile, if that's the question.

Xav


-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Doug Whitesell (LKML)


On Oct 14, 2007, at 4:01 PM, Rik van Riel wrote:


The kernel newbies community often gets inquiries from CS students who
need a project for their studies and would like to do something with
the Linux kernel, but would also like their code to be useful to the
community afterwards.

In order to make it easier for them, I am trying to put together a
page with projects that:
- Are self contained enough that the students can implement the
  project by themselves, since that is often a university requirement.
- Are self contained enough that Linux could merge the code (maybe
  with additional changes) after the student has been working on it
  for a few months.
- Are large enough to qualify as a student project, luckily there is
  flexibility here since we get inquiries for anything from 6 week
  projects to 6 month projects.

If you have ideas on what projects would be useful, please add them
to this page (or email me):

http://kernelnewbies.org/KernelProjects


I'm also quite interested in what compsci students can do for the  
kernel project. I'm currently doing a little embedded development and  
research at school, but I and a few others would jump at the chance  
to work on the kernel (besides finding duplicate problems that the  
x86 merge is already taking care of, of course. ;)


Also (as an aside), we're looking at redoing our operating systems  
curriculum out here at school...anyone aware of (relatively good) OS  
curricula? (time scope: one semester.)


regards/thanks,
--
Doug Whitesell
CSU Channel Islands - Computer Science
Unprecedented performance: nothing we had has ever worked like this  
before...

-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Zan Lynx
On Sun, 2007-10-14 at 19:01 -0400, Rik van Riel wrote:
 The kernel newbies community often gets inquiries from CS students who
 need a project for their studies and would like to do something with
 the Linux kernel, but would also like their code to be useful to the
 community afterwards.
 
 In order to make it easier for them, I am trying to put together a
 page with projects that:
 - Are self contained enough that the students can implement the
   project by themselves, since that is often a university requirement.
 - Are self contained enough that Linux could merge the code (maybe
   with additional changes) after the student has been working on it
   for a few months.
 - Are large enough to qualify as a student project, luckily there is
   flexibility here since we get inquiries for anything from 6 week
   projects to 6 month projects.
 
 If you have ideas on what projects would be useful, please add them
 to this page (or email me):
 
 http://kernelnewbies.org/KernelProjects

How about this in the Device Mapper raid-1/mirror code?
/* FIXME: add read balancing */

That comment has been in there for many releases.  I've wanted read
balancing for several servers and had all sorts of ideas about it, like
adding functions to the underlying device queues to return a queuing
cost to determine which is the best queue to add the read request.  I
think that could work better for queues like CFQ than the MD
closest-head.

An implementation would also need to be benchmarked against the MD
raid-1.

Along with the time to submit it to LKML, get it reviewed and polish it
up, it might make a good student project.
-- 
Zan Lynx [EMAIL PROTECTED]


signature.asc
Description: This is a digitally signed message part


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Mark Gross
On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
 The kernel newbies community often gets inquiries from CS students who
 need a project for their studies and would like to do something with
 the Linux kernel, but would also like their code to be useful to the
 community afterwards.
 
 In order to make it easier for them, I am trying to put together a
 page with projects that:
 - Are self contained enough that the students can implement the
   project by themselves, since that is often a university requirement.
 - Are self contained enough that Linux could merge the code (maybe
   with additional changes) after the student has been working on it
   for a few months.
 - Are large enough to qualify as a student project, luckily there is
   flexibility here since we get inquiries for anything from 6 week
   projects to 6 month projects.
 
 If you have ideas on what projects would be useful, please add them
 to this page (or email me):
 
 http://kernelnewbies.org/KernelProjects

Is there already a make config option that will do a good job at setting
a default .config file based on what is already running on a system?  

I get tiered of trimming down my .config for my laptop build so it takes
less than 30min to build a kernel.

Bonus credit to additional expert options (like those powertop puts
out) for target uses, laptop, HPC, home file share, embedded targets

Oh, and lets make the expert configs easily extensible.


--mgross


 
 thanks,
 
 Rik
 -- 
 Debugging is twice as hard as writing the code in the first place.
 Therefore, if you write the code as cleverly as possible, you are,
 by definition, not smart enough to debug it. - Brian W. Kernighan
 -
 To unsubscribe from this list: send the line unsubscribe linux-kernel in
 the body of a message to [EMAIL PROTECTED]
 More majordomo info at  http://vger.kernel.org/majordomo-info.html
 Please read the FAQ at  http://www.tux.org/lkml/
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Rik van Riel
On Mon, 15 Oct 2007 18:40:34 +0800
WANG Cong [EMAIL PROTECTED] wrote:

 http://kernelnewbies.org/KernelProjects
 
 Thanks very much, Rik. I need this eagerly.
 
 I want to find a kernel project that can both be my graduation thesis
 and contribute to the Linux kernel community. I read that page and
 think your project--Swapout Clustering is interesting for me.
 Is it alright for me to work on it? And can you give some help?

You would be the third student to take on that project
simultaneously.  That is not a problem for me (on the
contrary, it increases the chances of one codebase being
likeable to Linus), but it does decrease the chances of
your patch being the one to make it upstream.

Still, it should be a fun project to implement and
benchmark, so go ahead if you want.

-- 
Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it. - Brian W. Kernighan
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Rik van Riel
On Mon, 15 Oct 2007 11:10:32 -0600
Zan Lynx [EMAIL PROTECTED] wrote:

  http://kernelnewbies.org/KernelProjects
 
 How about this in the Device Mapper raid-1/mirror code?
   /* FIXME: add read balancing */
 
 That comment has been in there for many releases.  I've wanted read
 balancing for several servers and had all sorts of ideas about it,

I've written down the basic description:

http://kernelnewbies.org/KernelProjects/Raid1ReadBalancing

Could you add any ideas that you have to the page?
It is a wiki, so anybody can edit the site (after
creating an account).

-- 
Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it. - Brian W. Kernighan
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Guilherme Amadio
 Hello,

 I read the messages about the company list and now this CS projects list and
 I was wondering if is there any similar list of labs/universities that host
 PhD projects related to the Linux kernel. I am thinking about switching from
 physics to CS and it would be really cool to work with the kernel.

 Thanks in advance,

 Guilherme

-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread J. Bruce Fields
On Mon, Oct 15, 2007 at 03:30:41PM -0200, Guilherme Amadio wrote:
  I read the messages about the company list and now this CS projects list and
  I was wondering if is there any similar list of labs/universities that host
  PhD projects related to the Linux kernel. I am thinking about switching from
  physics to CS and it would be really cool to work with the kernel.

You might take a look at proceedings for conferences with recent
linux-related papers (linuxsymposium.org, usenix.org, linux.org.au, ?)
and look for urls and presenters with .edu addresses.

--b.
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Sam Ravnborg
On Mon, Oct 15, 2007 at 06:31:54PM +0200, Philippe Elie wrote:
  Increase speed for a build with no updates
  ==
  On a resonably fast machine with a decent config it takes
  roughly 10 seconds to do a make where nothing is updated.
  Generating one single Makefile is assumed to speed up things
  and will in addition allow a simpler syntax as what is used today
  for some of the uglier constructs.
  
  Contact: Sam Ravnborg [EMAIL PROTECTED]
  Difficulty: 5
  Language: Perl or C
 
 Isn't make -j 2 or more implemented by running multiple make in sub-dirs ?
 Parallel make is more and more used even on cheap hardware.

The kernel build system supports parallel make and I guess all
kernel developers use it. People tell me that a 32 way machine is
quite good for kernel compilation.

The bottleneck is that we spawn so many make instances and each have
to read all the same makefiles and stat in total a zillion files
for a simple kernel build.

With a single Makefile we can run a single instance make where
we read all files only once and stat the same file only once.

Sam
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Sam Ravnborg
On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
 On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
  The kernel newbies community often gets inquiries from CS students who
  need a project for their studies and would like to do something with
  the Linux kernel, but would also like their code to be useful to the
  community afterwards.
  
  In order to make it easier for them, I am trying to put together a
  page with projects that:
  - Are self contained enough that the students can implement the
project by themselves, since that is often a university requirement.
  - Are self contained enough that Linux could merge the code (maybe
with additional changes) after the student has been working on it
for a few months.
  - Are large enough to qualify as a student project, luckily there is
flexibility here since we get inquiries for anything from 6 week
projects to 6 month projects.
  
  If you have ideas on what projects would be useful, please add them
  to this page (or email me):
  
  http://kernelnewbies.org/KernelProjects
 
 Is there already a make config option that will do a good job at setting
 a default .config file based on what is already running on a system?  
I have discussed this briefly with Kay Sievers.
What udev can provide is the list of modules needed, so what the kernel
need to provide is a simple module to CONFIG option(s) converter + a base
config to start out with.
Nothing particular difficult but needs a few days work to do.

Sam
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Sam Ravnborg
On Mon, Oct 15, 2007 at 11:10:40AM -0400, Rik van Riel wrote:
 On Mon, 15 Oct 2007 16:23:52 +0200
 Sam Ravnborg [EMAIL PROTECTED] wrote:
 
   If you have ideas on what projects would be useful, please add them
   to this page (or email me):
   
   http://kernelnewbies.org/KernelProjects
  
  In the kernel build area a few possible projects exists.
 
 Thank you Sam, I have added your project ideas to the page.

Thanks for adding these.

Sam
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Mark Gross
On Mon, Oct 15, 2007 at 08:30:17PM +0200, Sam Ravnborg wrote:
 On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
  On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
   The kernel newbies community often gets inquiries from CS students who
   need a project for their studies and would like to do something with
   the Linux kernel, but would also like their code to be useful to the
   community afterwards.
   
   In order to make it easier for them, I am trying to put together a
   page with projects that:
   - Are self contained enough that the students can implement the
 project by themselves, since that is often a university requirement.
   - Are self contained enough that Linux could merge the code (maybe
 with additional changes) after the student has been working on it
 for a few months.
   - Are large enough to qualify as a student project, luckily there is
 flexibility here since we get inquiries for anything from 6 week
 projects to 6 month projects.
   
   If you have ideas on what projects would be useful, please add them
   to this page (or email me):
   
   http://kernelnewbies.org/KernelProjects
  
  Is there already a make config option that will do a good job at setting
  a default .config file based on what is already running on a system?  
 I have discussed this briefly with Kay Sievers.
 What udev can provide is the list of modules needed, so what the kernel
 need to provide is a simple module to CONFIG option(s) converter + a base
 config to start out with.
 Nothing particular difficult but needs a few days work to do.
 

that would be cool.

--mgross
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Alexey Dobriyan
On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
 On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
  http://kernelnewbies.org/KernelProjects
 
 Is there already a make config option that will do a good job at setting
 a default .config file based on what is already running on a system?  
 
 I get tiered of trimming down my .config for my laptop build so it takes
 less than 30min to build a kernel.

Ehh? You do it once, then leave it aside or in /proc/config.gz, on new
kernel copy it back, make oldconfig, answer several questions and here
we go.

 Bonus credit to additional expert options (like those powertop puts
 out) for target uses, laptop, HPC, home file share, embedded targets
 
 Oh, and lets make the expert configs easily extensible.
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Giacomo Catenazzi
Sam Ravnborg wrote:
 On Mon, Oct 15, 2007 at 10:04:11AM -0700, Mark Gross wrote:
 On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:
 The kernel newbies community often gets inquiries from CS students who
 need a project for their studies and would like to do something with
 the Linux kernel, but would also like their code to be useful to the
 community afterwards.

 In order to make it easier for them, I am trying to put together a
 page with projects that:
 - Are self contained enough that the students can implement the
   project by themselves, since that is often a university requirement.
 - Are self contained enough that Linux could merge the code (maybe
   with additional changes) after the student has been working on it
   for a few months.
 - Are large enough to qualify as a student project, luckily there is
   flexibility here since we get inquiries for anything from 6 week
   projects to 6 month projects.

 If you have ideas on what projects would be useful, please add them
 to this page (or email me):

 http://kernelnewbies.org/KernelProjects
 Is there already a make config option that will do a good job at setting
 a default .config file based on what is already running on a system?  
 I have discussed this briefly with Kay Sievers.
 What udev can provide is the list of modules needed, so what the kernel
 need to provide is a simple module to CONFIG option(s) converter + a base
 config to start out with.
 Nothing particular difficult but needs a few days work to do.

could you explain better what you need?  I think I've already such
tools ;-)

ciao
cate
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread Folkert van Heusden
   http://kernelnewbies.org/KernelProjects
  
  Is there already a make config option that will do a good job at setting
  a default .config file based on what is already running on a system?  
  
  I get tiered of trimming down my .config for my laptop build so it takes
  less than 30min to build a kernel.
 
 Ehh? You do it once, then leave it aside or in /proc/config.gz, on new
 kernel copy it back, make oldconfig, answer several questions and here
 we go.

Ah yes, but then you buy a new system to which the old config does not
apply.


Folkert van Heusden

-- 
www.vanheusden.com/multitail - win een vlaai van multivlaai! zorg
ervoor dat multitail opgenomen wordt in Fedora Core, AIX, Solaris of
HP/UX en win een vlaai naar keuze
--
Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread david

On Mon, 15 Oct 2007, Mark Gross wrote:


On Sun, Oct 14, 2007 at 07:01:28PM -0400, Rik van Riel wrote:

The kernel newbies community often gets inquiries from CS students who
need a project for their studies and would like to do something with
the Linux kernel, but would also like their code to be useful to the
community afterwards.

In order to make it easier for them, I am trying to put together a
page with projects that:
- Are self contained enough that the students can implement the
  project by themselves, since that is often a university requirement.
- Are self contained enough that Linux could merge the code (maybe
  with additional changes) after the student has been working on it
  for a few months.
- Are large enough to qualify as a student project, luckily there is
  flexibility here since we get inquiries for anything from 6 week
  projects to 6 month projects.

If you have ideas on what projects would be useful, please add them
to this page (or email me):

http://kernelnewbies.org/KernelProjects


Is there already a make config option that will do a good job at setting
a default .config file based on what is already running on a system?

I get tiered of trimming down my .config for my laptop build so it takes
less than 30min to build a kernel.

Bonus credit to additional expert options (like those powertop puts
out) for target uses, laptop, HPC, home file share, embedded targets

Oh, and lets make the expert configs easily extensible.


another config thing that would be nice would be to take something like 
Rob Landley's miniconfig tool and make it work well enough to be 
integrated (it creates a version of .config that only contains the things 
that need to be set, not everything that's at a default that doesn't make 
any difference)


David Lang
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


Re: WANTED: kernel projects for CS students

2007-10-15 Thread david

On Mon, 15 Oct 2007, Zan Lynx wrote:


On Sun, 2007-10-14 at 19:01 -0400, Rik van Riel wrote:

The kernel newbies community often gets inquiries from CS students who
need a project for their studies and would like to do something with
the Linux kernel, but would also like their code to be useful to the
community afterwards.

In order to make it easier for them, I am trying to put together a
page with projects that:
- Are self contained enough that the students can implement the
  project by themselves, since that is often a university requirement.
- Are self contained enough that Linux could merge the code (maybe
  with additional changes) after the student has been working on it
  for a few months.
- Are large enough to qualify as a student project, luckily there is
  flexibility here since we get inquiries for anything from 6 week
  projects to 6 month projects.

If you have ideas on what projects would be useful, please add them
to this page (or email me):

http://kernelnewbies.org/KernelProjects


How about this in the Device Mapper raid-1/mirror code?
/* FIXME: add read balancing */

That comment has been in there for many releases.  I've wanted read
balancing for several servers and had all sorts of ideas about it, like
adding functions to the underlying device queues to return a queuing
cost to determine which is the best queue to add the read request.  I
think that could work better for queues like CFQ than the MD
closest-head.

An implementation would also need to be benchmarked against the MD
raid-1.

Along with the time to submit it to LKML, get it reviewed and polish it
up, it might make a good student project.


another couple of raid enhancements would be:

1. teach the system that a raid456 stripe is handled most efficiantly if 
treated as a single block of data


by this I mean that if you read one block from the stripe the system reads 
the entire stripe, so it should take this into account when doing 
read-ahead and not always throw away most of the data it read becouse it's 
outside the current readahead window (if nothing else, look at putting it 
on the tail of the LRU list instead of just forgetting it)


if you write one block of the stripe the system must read the stripe, then 
update two blocks of the stripe (the data block and the parity block), but 
if you are going to write the entire stripe out you can ignore whatever's 
there and just calculate the parity block from the data you are writing. 
this should make writing to a raid456 stripe as fast as writing to a raid0 
stripe (well, almost, you have one more block to write).



2. not directly a kernel project, create userspace tools that make 
managing raid and partitioning on linux as easy as the zfs tools



3. there is currently the ability to grow a raid56 array by adding a disk, 
but there is not the ability to take a raid5 array, add a disk and make 
the result a raid6 array.


David Lang
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


WANTED: kernel projects for CS students

2007-10-14 Thread Rik van Riel
The kernel newbies community often gets inquiries from CS students who
need a project for their studies and would like to do something with
the Linux kernel, but would also like their code to be useful to the
community afterwards.

In order to make it easier for them, I am trying to put together a
page with projects that:
- Are self contained enough that the students can implement the
  project by themselves, since that is often a university requirement.
- Are self contained enough that Linux could merge the code (maybe
  with additional changes) after the student has been working on it
  for a few months.
- Are large enough to qualify as a student project, luckily there is
  flexibility here since we get inquiries for anything from 6 week
  projects to 6 month projects.

If you have ideas on what projects would be useful, please add them
to this page (or email me):

http://kernelnewbies.org/KernelProjects

thanks,

Rik
-- 
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


WANTED: kernel projects for CS students

2007-10-14 Thread Rik van Riel
The kernel newbies community often gets inquiries from CS students who
need a project for their studies and would like to do something with
the Linux kernel, but would also like their code to be useful to the
community afterwards.

In order to make it easier for them, I am trying to put together a
page with projects that:
- Are self contained enough that the students can implement the
  project by themselves, since that is often a university requirement.
- Are self contained enough that Linux could merge the code (maybe
  with additional changes) after the student has been working on it
  for a few months.
- Are large enough to qualify as a student project, luckily there is
  flexibility here since we get inquiries for anything from 6 week
  projects to 6 month projects.

If you have ideas on what projects would be useful, please add them
to this page (or email me):

http://kernelnewbies.org/KernelProjects

thanks,

Rik
-- 
Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it. - Brian W. Kernighan
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/