Linux-Development-Sys Digest #132, Volume #8 Sat, 9 Sep 00 12:13:10 EDT
Contents:
Re: buffer_dirty - what's the @#$%? (Chris J/#6)
Re: buffer_dirty - what's the @#$%? (William Burrow)
Re: buffer_dirty - what's the @#$%? (Brian V. Smith)
dma with PCI bus ("Peter Huang")
Re: Threads on Linux ("Scott Simpson")
Wish for a writable ISO-9660 compatible filsystem (Otto Wyss)
Re: Swap Atomically? (Troy Loveday)
Shared libs question (MJ Dainty)
Help! (xing li)
2 ATM cards on one Linux box? ([EMAIL PROTECTED])
Re: Threads on Linux (Karl Heyes)
Re: Cross-compiler for powerpc-motorola-vxworks (Al Johnston)
Re: Threads on Linux ([EMAIL PROTECTED])
Re: Swap Atomically? (Larry Ebbitt)
Re: cursor settings (Kalle Olavi Niemitalo)
Re: Caching files from CD---problem when playing MP3s on CD (Frank Ranner)
kswapd (Wouter Verhelst)
Installing Win98, Win2000 and Linux on one PC?! (Shicheng)
----------------------------------------------------------------------------
From: [EMAIL PROTECTED] (Chris J/#6)
Crossposted-To: comp.os.linux.hardware,comp.os.linux.misc,comp.os.linux.questions
Subject: Re: buffer_dirty - what's the @#$%?
Reply-To: [EMAIL PROTECTED]
Date: 8 Sep 2000 20:47:27 +0100
Ken Walter <[EMAIL PROTECTED]> wrote:
>
>In a properly designed file system, caches should be written out
>to removable media as quickly as possible. If the user manages
>to remove the media before everything is written, the system should
>request the media be reinserted and then finish.
>Otherwise the removal should be an automatic dismount.
>Anything else is user unfriendly.
>
>Ken Walter
>
Wouldn't mounting the floppy with the 'sync' option solve this ?
Chris...
--
@}-,'-------------------------------------------------- Chris Johnson --'-{@
/ "(it is) crucial that we learn the difference / [EMAIL PROTECTED] \
/ between Sex and Gender. Therein lies the key / \
/ to our freedom" -- LB / www.nccnet.co.uk/~sixie \
------------------------------
From: [EMAIL PROTECTED] (William Burrow)
Crossposted-To: comp.os.linux.hardware,comp.os.linux.misc,comp.os.linux.questions
Subject: Re: buffer_dirty - what's the @#$%?
Date: 8 Sep 2000 20:23:40 GMT
Reply-To: [EMAIL PROTECTED]
On Fri, 08 Sep 2000 18:45:01 GMT,
Ken Walter <[EMAIL PROTECTED]> wrote:
>In a properly designed file system, caches should be written out
>to removable media as quickly as possible. If the user manages
The administrator who wishes such a policy (which it is: a policy, not a
design issue), should ensure that the sync option is specified for such
devices.
>to remove the media before everything is written, the system should
>request the media be reinserted and then finish.
This would be nice, but under certain weird circumstances the user
copying to the media may not be in control of the media. Technically,
removable media should be lockable such that someone with access to the
media cannot remove it while it is mounted.
--
William Burrow -- New Brunswick, Canada o
Copyright 2000 William Burrow ~ /\
~ ()>()
------------------------------
From: [EMAIL PROTECTED] (Brian V. Smith)
Crossposted-To: comp.os.linux.hardware,comp.os.linux.misc,comp.os.linux.questions
Subject: Re: buffer_dirty - what's the @#$%?
Date: 8 Sep 2000 21:03:45 GMT
In article <[EMAIL PROTECTED]>, [EMAIL PROTECTED] (William
Burrow) writes:
|> This would be nice, but under certain weird circumstances the user
|> copying to the media may not be in control of the media. Technically,
|> removable media should be lockable such that someone with access to the
|> media cannot remove it while it is mounted.
You mean like the floppy drive on the Mac? I've always hated it's fascistic policy
of not being to pop out the floppy by pushing a button, but for *nixes it makes
sense because of the caching.
--
===============================================================
Brian V. Smith ([EMAIL PROTECTED]) http://www-epb.lbl.gov/BVSmith
Lawrence Berkeley National Laboratory
I don't speak for LBL; they don't pay me enough for that.
Check out the xfig site at http://www-epb.lbl.gov/xfig
To the optimist, the glass is half full. To the pessimist, the
glass is half empty. To the engineer, the glass is twice as big
as it needs to be.
------------------------------
From: "Peter Huang" <[EMAIL PROTECTED]>
Subject: dma with PCI bus
Date: Fri, 8 Sep 2000 14:22:09 -0700
Hi all
Besides the Rubini book. Does any one knows where can I find good examples
of how DMA works with PCI bus?
thanks
Peter
------------------------------
From: "Scott Simpson" <[EMAIL PROTECTED]>
Subject: Re: Threads on Linux
Date: Fri, 08 Sep 2000 21:34:48 GMT
"Kaz Kylheku" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> On Wed, 06 Sep 2000 20:48:18 GMT, [EMAIL PROTECTED]
> <[EMAIL PROTECTED]> wrote:
> >Kaz Kylheku <[EMAIL PROTECTED]> wrote:
> >
> >> This readability comes at the cost of introducing the potential for
> >> race conditions and deadlocks, and execution order that differs from
> >> run to run even with identical inputs.
> >
> >Now that is patently false. There are large numbers of threaded
>
> I only said that the potential exists. There are whole classes of possible
> defects that can occur in multithreaded programs that don't exist in
single
> threaded programs.
>
> >programs which have no race conditions or deadlocks in them.
>
> No race conditions or no *known* race conditions?
What you should do is learn to prove that multithreaded programs don't have
race conditions. See Gerard Holzmann's "Design and Validation of Computer
Protocols".
------------------------------
From: [EMAIL PROTECTED] (Otto Wyss)
Crossposted-To: comp.os.linux.misc
Subject: Wish for a writable ISO-9660 compatible filsystem
Date: Fri, 8 Sep 2000 23:33:40 +0200
While I was reorganizing my backup (using a CD-writer), I had the idea
of using an ISO-9660 image file mounted through the loopback device. I
soon had to learn it won't work the way I liked since ISO-9660 is simply
readonly.
I think it's time Linux gets the ability to use writable image files, so
I'm going to make the following proposition:
1. Creating a writable ISO-9660 compatible fs (I'm calling it isorw)
- mounted on a writable device, writing/deleting/etc is possible
- written on a CD, it should be readable as if it were ISO-9660
- capable of Joliet and/or RockRigde extension
2. Creating tools to handle isorw
- kernel device drivers, readable part might be identical to ISO-9660
- mkimage for creating image files
- possible extension for CD writing programms
Q: Why a new filesystem
A: Sofar there is no fs for Linux which is writable on a disk and still
ISO-9660 combatible on a CD. Of course a writable image could be made
with ext2fs but it always needs special treatment if written to CD.
Q: Why ISO-9660 compatible
A: For archiving puroses (storing and retrieving on CD's for serveral
years) there aren't many alternatives. Vfat is one but not very
attractive to me. UDF might be another in a few year but not now since
not many computers can read UDF.
Q: How complicated is isorw
A: It depends on the way it's implemented. The reading part could
possible taken from the ISO driver. The writing part might be implementd
along the line of ISO-9660 Level 3 (as Rod Smith kindly suggested). IMHO
although I haven't read yet it I think it's doable.
Q: Why not simply changing the current ISO implementation.
A: This shouldn't be changed since lot of people needs it working.
Anyway if isorw is working it might be merged in later on.
Q: Could isorw be used on other systems, i.e. Windows
A: Of course but only readonly as an ordinary ISO-9660 file unless isorw
is implemented there as well.
Q: How about Joliet format
A: There shouldn't be a problem with Joliet and/or RockRidge extensions,
it should be handled as usual.
What are you thinking about my proposition? Could this be done or are
there obstacles I don't see. Is it alltogether not necessary, because
there's a much better solution?
Is there anyone who is interested in isorw as well and likes to help me.
I'm currently not a Linux/Unix developer, I mostly programmed on TANDEM
computers.
O. Wyss
------------------------------
From: Troy Loveday <[EMAIL PROTECTED]>
Subject: Re: Swap Atomically?
Date: 8 Sep 2000 21:51:05 GMT
Nix <$}xinix{[email protected]> wrote:
>[EMAIL PROTECTED] (Alexander Viro) writes:
>> mutexes (muteces? probably not
>Not. It is `mutexes'.
>(Not, as I saw used once, `mutii'. Gaaaah.)
For me, `mutexen' has a certain whimsical appeal.
--
Troy Loveday e-mail: <[EMAIL PROTECTED]>
------------------------------
From: MJ Dainty <[EMAIL PROTECTED]>
Subject: Shared libs question
Date: Sat, 9 Sep 2000 00:45:55 GMT
Hi,
I'm trying to write some code that uses some shared libs via the
dlopen/sym/... calls. Currently I'm having problems with making use of
the _init and _fini functions in the lib code, I get...
/tmp/ccaBGSQx.o: In function `_init':
/tmp/ccaBGSQx.o(.text+0x30): multiple definition of `_init'
/usr/lib/crti.o(.init+0x0): first defined here
/tmp/ccaBGSQx.o: In function `_fini':
/tmp/ccaBGSQx.o(.text+0x38): multiple definition of `_fini'
/usr/lib/crti.o(.fini+0x0): first defined here
collect2: ld returned 1 exit status
I'm declaring the functions as void _init() {} and void _fini() {} in
the lib code and compiling them with:
gcc -shared -o libname.so foo.c bar.c
Does anyone know what I'm doing wrong?
Thanks
Matt
------------------------------
From: xing li <[EMAIL PROTECTED]>
Subject: Help!
Date: Fri, 08 Sep 2000 20:57:30 -0400
Reply-To: [EMAIL PROTECTED]
I am just starting learning kernel module programming.
I compiled the character device example in "Linux kernel module
programming guide".
When I tried to load the module, I got the following message
>insmod chardev.o
chardev.o: unresolved symbol __put_user__X
chardev.o: unresolved symbol sprintk
Does anyone can tell me what is the problem? Thank you in advance.
The following is part of the code using these two functions, and I use
SUSE Linux 6.1 with kernel 2.2.5.
static int device_open(struct inode *inode, struct file *file)
{
static int counter = 0;
#ifdef DEBUG
printk("device_open(%p, %p)\n", inode, file);
#endif
printk("Device: %d.%d\n", inode->i_rdev>>8, inode->i_rdev & 0xFF);
if( Device_Open)
return -EBUSY;
Device_Open++;
sprintk(Message, "If I told you once, I told you %d times - $s",
counter++, "Hello world\n");
Message_Ptr = Message;
MOD_INC_USE_COUNT;
return SUCCESS;
}
static ssize_t device_read(struct file* file, char* buffer, size_t
length, loff_t *offset)
{
int bytes_read = 0;
if( *Message_Ptr == 0 )
return 0;
while( length && * Message_Ptr )
{
put_user(*(Message_Ptr++), buffer++);
length --;
bytes_read ++;
}
return bytes_read;
}
------------------------------
From: [EMAIL PROTECTED]
Subject: 2 ATM cards on one Linux box?
Date: Sat, 09 Sep 2000 00:59:55 GMT
Is this possible with ATM on Linux? I'm just trying to do some
simple testing with the cards with no switch.
Sent via Deja.com http://www.deja.com/
Before you buy.
------------------------------
From: Karl Heyes <[EMAIL PROTECTED]>
Subject: Re: Threads on Linux
Date: Sat, 09 Sep 2000 03:45:59 +0000
In article <YXcu5.32485$[EMAIL PROTECTED]>, "Scott
Simpson" <[EMAIL PROTECTED]> wrote:
>
>>
>> I only said that the potential exists. There are whole classes of possible
>> defects that can occur in multithreaded programs that don't exist in
> single
>> threaded programs.
>>
>> >programs which have no race conditions or deadlocks in them.
>>
>> No race conditions or no *known* race conditions?
>
> What you should do is learn to prove that multithreaded programs don't have
> race conditions. See Gerard Holzmann's "Design and Validation of Computer
> Protocols".
>
Surely thats impossible!. If threads share the data area then some style of
locking is required, get your locks wrong, you have a race condition?. am I
missing something.
karl.
------------------------------
From: Al Johnston <[EMAIL PROTECTED]>
Crossposted-To: gnu.gcc.help
Subject: Re: Cross-compiler for powerpc-motorola-vxworks
Date: Fri, 08 Sep 2000 22:45:08 -0400
> spending a lot of time digging around the internals of gcc and the WRS
> toolchain lately, in order to get 2.95.2 working with powerpc-wrs-vxworks,
> and I'm shortly going to post a FAQ/HowTo and set of patches addressing
> the issues in getting it up and running in a WRS development environment.
I cant wait!!! well, actually I can... I am planning to start down this
path shortly... So I am VERY interested in such a FAQ/HOWTO. I have
been building gcc solaris native for many years, but have never gotten
up the nerve to try a cross. We are now porting to powerpc, so now
is the time.
If your taking names, take mine!
thanks,
-al
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: Threads on Linux
Date: Sat, 09 Sep 2000 03:32:24 GMT
Karl Heyes <[EMAIL PROTECTED]> wrote:
> Surely thats impossible!. If threads share the data area then some style of
> locking is required, get your locks wrong, you have a race condition?. am I
> missing something.
Yes, the case where:
1. No threads modify the data segment.
2. Access to the data segment is authored so they aren't reading the
same portion at the same time. (By design of the algorithm, not
enforced by locking)
--
Matt Gauthier <[EMAIL PROTECTED]>
------------------------------
Date: Sat, 09 Sep 2000 06:24:07 -0400
From: Larry Ebbitt <[EMAIL PROTECTED]>
Subject: Re: Swap Atomically?
Troy Loveday wrote:
>
>
> >(Not, as I saw used once, `mutii'. Gaaaah.)
>
> For me, `mutexen' has a certain whimsical appeal.
How about "mutaphim?"
--
Larry Ebbitt - Linux + OS/2 - Atlanta
------------------------------
Crossposted-To: comp.os.linux.misc
Subject: Re: cursor settings
From: Kalle Olavi Niemitalo <[EMAIL PROTECTED]>
Reply-To: Kalle Olavi Niemitalo <[EMAIL PROTECTED]>
Date: 09 Sep 2000 15:54:43 +0300
Followups set.
[EMAIL PROTECTED] (B.Lim) writes:
> Is there a way to change the colour as well? I've read
> VGA-softcursor.txt in the source tree but it doesn't say how to compile
> it in the kernel - only through crude 'echo' commands.
You can change the color with the crude 'echo' commands. Edit
the number in front of the 'c'.
> I've tried
> modifying /usr/src/linux/include/linux/console_struct.h but I don't
> know how to disable the blinking. Any suggestions?
Try changing CUR_DEFAULT in that file. To 0x200011, for example.
Its relation to '\e[?c' numbers is in linux/drivers/char/console.c:
cursor_type = par[0] | (par[1]<<8) | (par[2]<<16);
------------------------------
From: Frank Ranner <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.misc
Subject: Re: Caching files from CD---problem when playing MP3s on CD
Date: Sun, 10 Sep 2000 00:31:42 +1100
Bruce Stephens wrote:
>
> Nix <$}xinix{[email protected]> writes:
>
> > Bruce Stephens <[EMAIL PROTECTED]> writes:
> >
> > > The same sort of idea strikes me as possible for what I want: I just
> > > need a user-mode filesystem (and I'm sure I've seen such things
> > > around, although I don't recall the name), and it could layer on the
> > > CDROM---each time a file is opened, it could copy it to somewhere on
> > > the hard disk and operate on that. Similarly, these temporary copies
> > > could be deleted.
> >
> > This sounds pretty much exactly like union-mounting, only COW.
> >
> > Does Linux-2.4's union mounting support COW like that? (I don't have the
> > 2.4 kernel here atm because of a crisis involving `rm -r' and fingers
> > typing faster than brain, so I can't easily tell.)
>
> Don't I want copy-on-read? I'm not intending to try to change the
> MP3's (or Ogg files or whatever)---just read them.
>
> However, that's a plausible place to look: if I had a union mounting
> system which did COW, then perhaps it would be easy to make one which
> did COR instead.
I saw something like that on an old Linux distribution called Linux-Ft.
It had a
caching scheme that worked like this:
You create a directory and put in a control file that nominated how many
megs the
directory would hold and where the source data was. Then all the files
in the destination
were symbolic linked from the source directory. Now, when the file was
opened, the file
system code noticed the symbolic link, and replaced it with the real
file, and then proceeded
with the open. Once the directory got to the pre-ordained number of
megs, it started to free up
space by blowing away files based on access time, replacing them with
the original symbolic link.
The original idea was to run live of the CD, with your working set of
programs migrating to hard
disk. I havent seen this since, presumably because hard disk got bigger
and cdroms got faster.
Regards, Frank Ranner
------------------------------
From: [EMAIL PROTECTED] (Wouter Verhelst)
Subject: kswapd
Date: Sat, 09 Sep 2000 14:29:15 GMT
Hi!
I've been wondering lately what the function of kswapd is. I don't
assume the kernel will no longer be able to swap when kswapd gets
killed for some reason, but in that case I don't see the "raison
d'etre" for kswapd.
Could someone explain to a graduate in Information Technology (at
least, if I pass my last examinations ;-) what the function of kswapd
is?
TIA,
Wouter
--
4:25pm up 1:51, 2 users, load average: 1.07, 1.26, 1.22
Voor een vertaling van Documentation/Configure.help naar het Nederlands:
http://users.pandora.be/wouter.verhelst/configure.html
Andrea: Unhappy the land that has no heroes.
Galileo: No, unhappy the land that _____needs heroes.
-- Bertolt Brecht, "Life of Galileo"
------------------------------
From: Shicheng <[EMAIL PROTECTED]>
Crossposted-To: alt.os.linux,comp.os.linux.setup,microsoft.public.win2000.applications
Subject: Installing Win98, Win2000 and Linux on one PC?!
Date: Sat, 09 Sep 2000 15:13:24 GMT
Hello there,
We would like to install Win98, Win2000 and linux (redhat 6.0)
three OSs onto our PC. The PC has a 30 GB hard disk, 128 MB memory
and a 700 MHz CPU.
We would like to have the above three OSs installed; after the
installation, we could select one of the three OSs during the boot time,
otherwise, the PC will be booted automatically to the default
OS (Win 2000 is the default one). Each OS would use one partition,
so the three OSs would need three partitions.
Apart from these three OS partitions, we may also need to create
two more partitions using the remaining space of the disk:
one such a partition would be for the storage of linux's data and the
other one would be for the data storage for both the Win98 and Win2000
OSs; so the last data partition needs to be seen by both the 98 and the
2000 OSs.
We would be grateful you could give us some advice on the above.
Thanks,
Shicheng
Sent via Deja.com http://www.deja.com/
Before you buy.
------------------------------
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End of Linux-Development-System Digest
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