Linux-Development-Sys Digest #956, Volume #7 Fri, 16 Jun 00 08:13:09 EDT
Contents:
HELP hard drive error?? ("Nick Rout")
Re: A strange problem using poll() systemcall (Mario Klebsch)
how to make user belong to more than 32 groups(empty) (Jerry)
Re: HELP hard drive error?? (thing)
Re: A strange problem using poll() systemcall (Villy Kruse)
virtual filesystems? (Erik Terpstra)
Re: HELP hard drive error?? ("Dave Rave")
Re: Device driver programming (Wolfram Faul)
Re: Use of insmod (Chetan Ahuja)
Pseudo terminals and PPP (Craig Allan Jeffree)
where can i find a HOW TO in order to insert a new system call in linux kernel?
("Paolo Romano")
Re: Linux Application Server (Chetan Ahuja)
Re: syscall ("V.Vijay Kumar")
Re: syscall ("V.Vijay Kumar")
Re: virtual filesystems? (Winston Avalon)
R: Inserting a new system call ("@LeX")
Re: HELP hard drive error?? (Munge)
Kernel memory and DMA (Carlton Teel)
----------------------------------------------------------------------------
From: "Nick Rout" <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.hardware,nz.comp
Subject: HELP hard drive error??
Date: Fri, 16 Jun 2000 16:23:26 +1200
Can anyone tell me what this means in my linux logs
Jun 16 11:32:01 gw kernel: hda: read_intr: status=0x59 { DriveReady
SeekComplete DataRequest Error }
Jun 16 11:32:01 gw kernel: hda: read_intr: error=0x40
{ UncorrectableError }, LBAsect=565844, sector=565781
Jun 16 11:32:01 gw kernel: end_request: I/O error, dev 03:01 (hda), sector
565781
Its recurring a lot. I suspect my hard drive is about to give up the ghost,
which is not too cool.
Can anyone give me a definitive analysis. It GENERALLY seems to be the same
sector number.
------------------------------
From: [EMAIL PROTECTED] (Mario Klebsch)
Subject: Re: A strange problem using poll() systemcall
Date: Thu, 15 Jun 2000 23:04:05 +0200
"Roman A. Stepanov" <[EMAIL PROTECTED]> writes:
><[EMAIL PROTECTED]> wrote:
>> You are invoking poll every millisecond, which is very inefficient.
>> Consider what value of the third argument you really want, bearing in
>> mind that it's in milliseconds not seconds.
> Yes, I have to check if there any incoming data _every_ millisecond
>because
> it's very important to me to check some particular device connected to
>the
> serial port at least 100 times per second. I'd be grateful if anybody
>tells me
> how to do it as much faster as possible!
You only need the timeout of 1ms, if you have other things to do every
1ms. If you only want to get input from the serial port, you do not
need to use poll() at all, read() will do just fine.
73, Mario
--
Mario Klebsch [EMAIL PROTECTED]
------------------------------
From: Jerry <[EMAIL PROTECTED]>
Subject: how to make user belong to more than 32 groups(empty)
Date: Fri, 16 Jun 2000 12:55:28 +0800
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is there a options I can set or do I need to recompile the kernel,if
recompiled is needed,where to set that group limit
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------------------------------
From: thing <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.hardware,nz.comp
Subject: Re: HELP hard drive error??
Date: Fri, 16 Jun 2000 17:25:10 +1200
I have had 2 similar errors off my email server, at first I thought I needed to
reformat the HD and it was then fine, about a year later it started again and
turned out to be the PSU.
First thing is run fsck that fixed the problems for me. See if re-occurs.
Thing
Nick Rout wrote:
> Can anyone tell me what this means in my linux logs
>
> Jun 16 11:32:01 gw kernel: hda: read_intr: status=0x59 { DriveReady
> SeekComplete DataRequest Error }
> Jun 16 11:32:01 gw kernel: hda: read_intr: error=0x40
> { UncorrectableError }, LBAsect=565844, sector=565781
> Jun 16 11:32:01 gw kernel: end_request: I/O error, dev 03:01 (hda), sector
> 565781
>
> Its recurring a lot. I suspect my hard drive is about to give up the ghost,
> which is not too cool.
>
> Can anyone give me a definitive analysis. It GENERALLY seems to be the same
> sector number.
------------------------------
From: [EMAIL PROTECTED] (Villy Kruse)
Subject: Re: A strange problem using poll() systemcall
Date: 16 Jun 2000 07:50:49 GMT
On Thu, 15 Jun 2000 23:04:05 +0200, Mario Klebsch <[EMAIL PROTECTED]> wrote:
>"Roman A. Stepanov" <[EMAIL PROTECTED]> writes:
>><[EMAIL PROTECTED]> wrote:
>
>>> You are invoking poll every millisecond, which is very inefficient.
>>> Consider what value of the third argument you really want, bearing in
>>> mind that it's in milliseconds not seconds.
>
>> Yes, I have to check if there any incoming data _every_ millisecond
>>because
>> it's very important to me to check some particular device connected to
>>the
>> serial port at least 100 times per second. I'd be grateful if anybody
>>tells me
>> how to do it as much faster as possible!
>
>You only need the timeout of 1ms, if you have other things to do every
>1ms. If you only want to get input from the serial port, you do not
>need to use poll() at all, read() will do just fine.
>
This is approaching requirements for a real-time operating system, and
linux and most other unix-like systems are not designed for this. In
most cases your process won't get a chance to run until the next clock
tick which occurs once every 10 miliseconds. For 1 milisecond responce
time you probably would need to program the whole thing into a device
driver where the incomming character can be handled as soon as the
serial device interrupt occur.
Villy
------------------------------
Date: Fri, 16 Jun 2000 09:56:34 +0200
From: Erik Terpstra <[EMAIL PROTECTED]>
Subject: virtual filesystems?
Hi,
Is it somehow possible to mount the examples below as if it were a
filesystem?
- FTP, with id/passwd it acts as r/w, otherwise it is mounted as
read-only.
- HTTP, acts read-only, if it supports WebDAV it can be r/w.
- CVS
- TAR
- TAR.GZ
- TAR.BZ2
- NNTP, cd /mnt/nntp.test.net, ls to see newsgroups, cd alt.anonymous,
ls to see messages, cat somemsg
- POP or IMAP, ls to see messages, cat or your favourite editor to read
them, cd into different mailfolders.
etc. etc.
Regards,
Erik.
------------------------------
From: "Dave Rave" <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.hardware,nz.comp
Subject: Re: HELP hard drive error??
Date: Fri, 16 Jun 2000 20:18:59 +1200
it means Linus needs to do some work on error messages :)
"Nick Rout" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]...
> Can anyone tell me what this means in my linux logs
>
> Jun 16 11:32:01 gw kernel: hda: read_intr: status=0x59 { DriveReady
> SeekComplete DataRequest Error }
> Jun 16 11:32:01 gw kernel: hda: read_intr: error=0x40
> { UncorrectableError }, LBAsect=565844, sector=565781
> Jun 16 11:32:01 gw kernel: end_request: I/O error, dev 03:01 (hda), sector
> 565781
>
> Its recurring a lot. I suspect my hard drive is about to give up the
ghost,
> which is not too cool.
>
> Can anyone give me a definitive analysis. It GENERALLY seems to be the
same
> sector number.
>
>
------------------------------
From: Wolfram Faul <[EMAIL PROTECTED]>
Subject: Re: Device driver programming
Date: Fri, 16 Jun 2000 10:44:30 +0200
Grant Edwards wrote:
> In article <[EMAIL PROTECTED]>, Joseph Lyman wrote:
>
> >Programming is one of my passions, but I havent done any device drivers yet.
> >any tips or places to start? All information would be greatly appreciated.
>
> _Linux_Device_Drivers_ by Rubini is a good place to start. You
> need to be aware that it's a little dated. Most of the
>
Yes, it�s a bit old especially if you use the 2.4 kernel. But the book describes
the basics very good, so it�s
possible to transfer it to newer kernel. You have good hints where to look.
> examples are done with a 2.0 kernel and there's a chapter at
> the end discussing 2.0-2.1 differences.
>
> Still, it's an excellent introduction to how device drivers
> work.
>
> --
> Grant Edwards grante Yow! If I felt any more
> at SOPHISTICATED I would DIE
> visi.com of EMBARRASSMENT!
Also have a look at this site
http://www.linuxdoc.org/guides.html
There is the "The Linux Kernel Module Programming Guide" it�s very good and
newer then the book. But you don�t learn something about taskqueues and
interrupthandling.
Wolfram
------------------------------
From: Chetan Ahuja <[EMAIL PROTECTED]>
Subject: Re: Use of insmod
Date: 16 Jun 2000 08:53:17 GMT
Robichaud, Jean-Philippe [BAN:6S33:EXCH] <[EMAIL PROTECTED]> spoke thusly:
>>
>> There's the Linux Kernel Hacker's Guide at the linux documentation project. It's a
>bit old but will provide some hints
>>
>> http://metalab.unc.edu/mdw/index.html
>>
> This guide is not avaiable on the net anymore, can you post it on the
> newsgroup, I'm sure it will help a lot of us ! (If it is not too big !)
> Thanks a lot
> Jean-Philippe Robichaud
It's availabel on linuxdoc.org under the "guides" section..
Chetan
------------------------------
From: Craig Allan Jeffree <[EMAIL PROTECTED]>
Crossposted-To:
comp.os.linux.misc,comp.os.linux.development.apps,comp.os.linux.networking
Subject: Pseudo terminals and PPP
Date: Fri, 16 Jun 2000 18:33:46 +1000
Hello all,
I'm trying to setup a server which will be accepting data from a
network. This data will consist of packets in a protocol designed for a
special modem we have. These packets will contain PPP packets. We wish
to be able to maintain hundreds of thousands of PPP links to different
devices. I have been looking for a PPP server which can make lots of
connections on one port but havn't been able to find one.
Does anyone know of a PPP server which can be pointed to a
Pseudo terminal and accept packets from lots of PPP sessions all from
the same terminal. I have had a look at putting an application on the
terminal which de-multiplexes all these PPP sessions to a single Pseudo
terminal each but I cannot figure out how to have more than 256 pseudo
terminals under linux - and it doesn't seem feasable to have so many
active pppd processes each with a pseudo terminal pair open. I would
really like to avoid having to write a PPP server myself as we are
pushing a deadline.
If anyone can offer some suggestions it would be a great help.
Thanks for your advice
Craig Jeffree
dotWAP
------------------------------
From: "Paolo Romano" <[EMAIL PROTECTED]>
Subject: where can i find a HOW TO in order to insert a new system call in linux
kernel?
Date: Fri, 16 Jun 2000 10:55:55 +0200
------------------------------
From: Chetan Ahuja <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.networking,comp.os.linux.setup
Subject: Re: Linux Application Server
Date: 16 Jun 2000 09:02:06 GMT
In comp.os.linux.development.system Conrad Mukai <[EMAIL PROTECTED]> wrote:
> I was interested in anyone's experience with serving up programs through
> an NFS mount of /usr from an applications server. I've done some
> experiments and found that the most annoying thing to be that the
> shutdown sequence does not account for mounts of /usr causing shutdown
> to take on the order of 5-10 minutes. Since the Linux users in my
> network rarely reboot, this is only considered to be a minor
> incovenience. What concerns me more is upgrading to new distributions.
> Since /lib must reside on each client for booting up, would I have to
You can remount the /lib over nfs too after the boot sequence is
over. Just keep the minimal amount required under /lib ( what is it
anyway... /lib/modules ??) for bootin to go through. But I do
suspect that there is no such requirement if you compile your
network drivers into the client machine kernels, you should be able
to do the rest over NFS. Don't people make diskless terminals with
linux (Booting through the network card ROM... ??) Go through the
relevant howto's again.
And as for shutdown sequence worries... you could change the
sequence yourself. Shouldn't be a big deal... just add a small
script that changes mtab ( to get rid of /usr) before the
umount -a takes effect??? or am I missing something here.
Chetan
------------------------------
From: "V.Vijay Kumar" <[EMAIL PROTECTED]>
Subject: Re: syscall
Date: Fri, 16 Jun 2000 14:55:20 +0530
Have u recompiled the kernel? If u havent this is how u do it:
Goto /usr/src/linux
Place ur system call .c file in the kernel sub dir
Then add the entry of .o file for OBJS in the Makefile
Now for recompiling:
make config
make depend
make
make boot
The new kernel is found as arch/i386/boot/zImage
--
Vijay
"@LeX" <aleefaby*NOSPAM*@libero.it> wrote in message
news:8Bb25.205970$[EMAIL PROTECTED]...
> Hi all!
> I'm searching for someone can help me about this question:
> I'm tryin' to write a new syscall that makes atomic sys_lseek and
sys_write
> (I'll call it atomic_read from here)
> I've added a new entry for that in the entry.S and <linux/unistd.h>
files.
> I've also updated the counter in the entry.S file.
> I've placed the prototype for atomic_read in <unistd.h>.
> Ok... now that's the question :
> I've written a small program to test atomic read.
> I've compiled it with the follow string :
> $gcc -O2 -Wall my_read_test.c -o my_test
> the result is an error from the linker, which doesn't resolve the
reference
> to atomic_read.
> Where's the error??
> Thanx
>
> @LeX
>
> #define __TRUE__ "C is Better"
>
>
------------------------------
From: "V.Vijay Kumar" <[EMAIL PROTECTED]>
Subject: Re: syscall
Date: Fri, 16 Jun 2000 14:55:57 +0530
Have u recompiled the kernel? If u havent this is how u do it:
Goto /usr/src/linux
Place ur system call .c file in the kernel sub dir
Then add the entry of .o file for OBJS in the Makefile
Now for recompiling:
make config
make depend
make
make boot
The new kernel is found as arch/i386/boot/zImage
--
Vijay
"@LeX" <aleefaby*NOSPAM*@libero.it> wrote in message
news:8Bb25.205970$[EMAIL PROTECTED]...
> Hi all!
> I'm searching for someone can help me about this question:
> I'm tryin' to write a new syscall that makes atomic sys_lseek and
sys_write
> (I'll call it atomic_read from here)
> I've added a new entry for that in the entry.S and <linux/unistd.h>
files.
> I've also updated the counter in the entry.S file.
> I've placed the prototype for atomic_read in <unistd.h>.
> Ok... now that's the question :
> I've written a small program to test atomic read.
> I've compiled it with the follow string :
> $gcc -O2 -Wall my_read_test.c -o my_test
> the result is an error from the linker, which doesn't resolve the
reference
> to atomic_read.
> Where's the error??
> Thanx
>
> @LeX
>
> #define __TRUE__ "C is Better"
>
>
------------------------------
From: [EMAIL PROTECTED] (Winston Avalon)
Subject: Re: virtual filesystems?
Date: Fri, 16 Jun 2000 09:44:51 GMT
On Fri, 16 Jun 2000 09:56:34 +0200, Erik Terpstra <[EMAIL PROTECTED]>
wrote:
>Hi,
>
>Is it somehow possible to mount the examples below as if it were a
>filesystem?
>
>- FTP, with id/passwd it acts as r/w, otherwise it is mounted as
>read-only.
>- HTTP, acts read-only, if it supports WebDAV it can be r/w.
>- CVS
>- TAR
>- TAR.GZ
>- TAR.BZ2
>- NNTP, cd /mnt/nntp.test.net, ls to see newsgroups, cd alt.anonymous,
>ls to see messages, cat somemsg
>- POP or IMAP, ls to see messages, cat or your favourite editor to read
>them, cd into different mailfolders.
>etc. etc.
>
>Regards,
>
> Erik.
For http and ftp, try perlfs
for zip, try userfs
------------------------------
From: "@LeX" <aleefaby*NOSPAM*@libero.it>
Subject: R: Inserting a new system call
Date: Fri, 16 Jun 2000 09:40:18 GMT
Paolo Romano <[EMAIL PROTECTED]> wrote in message
8ibdar$n2n$[EMAIL PROTECTED]
> I need to insert a new system call which is similar to read() and that
i'll
> be refering to as atomic_read()
> I have added in the sys_call_table in entry.s the entry sys_atomic_read
and
> I've updated the number of total entries
> I have inserted in unistd.h (sorry at the moment I can't verify the path
of
> these files, i hope you can help me anyway), the one with the numbers
> associated to each system call the correct number for my own system call
> In the unistd.h which contains part of the GNU librart and in particular
the
> prototypes for read and write i have added the prototype of my
atomic_read.
> I have added the code of my system call in fs/read_write.c which is the
file
> where is found the code for sys_read and sys_write
>
> I could compile the kernel without any problem. But when i use a C program
> including unistd.h (which is need for using read) to test my system call
the
> compiler says it's unreferenced and returns a linkage error
>
> HELP ME IF YOU CAN!!!
>
> Thanks,
>
> Paolo Romano
>
>Che fai... chiedi aiuto???
Alessio :)))))))))))))))
------------------------------
From: Munge <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.hardware,nz.comp
Subject: Re: HELP hard drive error??
Date: 16 Jun 2000 08:52:45 GMT
In nz.comp Nick Rout <[EMAIL PROTECTED]> wrote:
: Can anyone give me a definitive analysis. It GENERALLY seems to be the same
: sector number.
Not really.
If you have an IDE drive it should automatically remap bad
sectors, unless it has run out of space. Run "badblocks" on
the partition in question and see if that comes up with something.
If it does detect a bad sector you'll have to reformat the drive
using the bad blocks option.
------------------------------
From: Carlton Teel <[EMAIL PROTECTED]>
Subject: Kernel memory and DMA
Date: Fri, 16 Jun 2000 12:02:44 GMT
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------------------------------
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