Un-killable process???

Un-killable process???

[Dean McBride]

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


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Re: Un-killable process???

[Julien Eyries]

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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Re: Un-killable process???

[Dean McBride]

Thanks for the response!

I'm actually using wait_event_interruptible() in my driver.  I also setup a
timeout timer to wake me up if for some reason the interrupt doesn't occur.
When I see the problem (Note it doesn't always happen ;(), I notice my
timer executes, but the process still seems to be hung.  One other note,
I'm also using kernel semaphores to protect the registers of the hardware
I'm communicating with during this time.  I've added ioctl()'s to the
driver to
issue up()'s to attempt to release the semaphore and also
wake_up_interruptible()
ioctls to attempt to wakeup the task.  These seem to execute fine, but the
process stay's hung!

Are there any tools, /proc files that can tell me where my task is hung?

The PMC card I'm communicating with is a LM1 ADC/DAC card, where I
have 2 task reading from & writing to the card.

Thanks again for your reply, any other suggestions are greatly appreciated!

Dean


At 11:20 AM 5/22/2002 +0200, Julien Eyries wrote:

>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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