From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <3CEB62F0.2080302@thales-bm.com>
Date: Wed, 22 May 2002 11:20:48 +0200
From: Julien Eyries <julien.eyries@thales-bm.com>
MIME-Version: 1.0
To: Dean McBride <dmcbride@sgss.com>,
	linuxppc-embedded@lists.linuxppc.org
Subject: Re: Un-killable process???
References: <5.1.0.14.0.20020521144711.0312fc28@sgss.com>
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Sender: owner-linuxppc-embedded@lists.linuxppc.org
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I have had the same problem when writing a driver for my custom hardware
; It's a well known problem, I found it explained in "Linux Device
Drivers" by Rubini & Corbet. (i have the french version , it's in chapter 5)
your driver should use the function "interruptible_sleep_on()" instead
of "sleep_on()" to block the process .
if you use "sleep_on()", your process will not receive any signal while
blocked and then could become "un-killable" .

bye.


Julien


Dean McBride wrote:

>
> Hello,
>
> I have a process I can't kill (kill -9) without rebooting the system.  I've
> attempted
> attaching strace, gdb, etc. to the process, but each of those task just
> hang.  I
> can however kill those task (strace, gdb).  I've looked through the
> /proc/<pid>
> area, but don't really know what I'm looking for or at!  The task seems
> to be
> somehow stuck on some resource, but I don't know which one or how to find
> out.  I'm running with Linux 2.4.10-pre10 on a 4 processor Power PC with
> 512Mbytes of memory.  The process is reading data from a PMC card.
>
> Any ideas or suggestions?  I've include some more information below!
>
> Thanks
> Dean
>
> Here's the output from the ps command:
>    74 root     root     R /opt/ds/src/lm1/bin/lm1_read -s 4 -m 255 -f 4000
> -a -r -u 2 -g 1
>
>
> Heres the /proc/74/status file
>
> sh-2.03# more /proc/74/status
> Name:   lm1_read
> State:  R (running)
> Pid:    74
> PPid:   62
> TracerPid:      0
> Uid:    0       0       0       0
> Gid:    0       0       0       0
> FDSize: 256
> Groups: 0
> VmSize:     2580 kB
> VmLck:      2580 kB
> VmRSS:      2580 kB
> VmData:     1128 kB
> VmStk:        16 kB
> VmExe:        20 kB
> VmLib:      1188 kB
> SigPnd: 0000000000044102
> SigBlk: 0000000000000000
> SigIgn: 8000000000000000
> SigCgt: 0000000000004002
> CapInh: 0000000000000000
> CapPrm: 00000000fffffeff
> CapEff: 00000000fffffeff
>
> /proc/74/statm file
>
> sh-2.03# more /proc/74/statm
> 645 645 317 17 0 628 328
>
>
>


--
Julien Eyries
R&D engineer
Thales Broadcast & Multimedia (ex-thomcast)
email: julien.eyries@thales-bm.com
fax: 33(0) 1 34 90 31 10
tel: 33(0) 1 34 90 31 01


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