Re: 2.6.17-rt1 - mm_struct leak

From: Mark Hounschell
Date: Sat Jun 24 2006 - 05:31:52 EST


Mark Hounschell wrote:
> Vernon Mauery wrote:
>> On Sunday 18 June 2006 00:06, Ingo Molnar wrote:
>>> i have released the 2.6.17-rt1 tree, which can be downloaded from the
>>> usual place:
>> I was given a test case to run that seemed to cause the machine to run the
>> OOM-killer after a bunch of iterations. The test was run like:
>>
>> $ for ((i=0;i<50000;i++)); do ./test; done
>>
>> and somewhere in there, the LowFree would drop very low and the test and the
>> bash shell running it would get killed. And then since that didn't free up
>> much memory, the machine would become very unresponsive and would have to be
>> rebooted.
>>
>> I don't have the source for the test myself and I am still trying to reproduce
>> it, but from what I have gathered, there is a problem cleaning up after
>> tasks. I monitored the machine with slabtop while running the loop and found
>> that the size-32, pgd, pgm, and mm_struct slabs caches were constantly
>> growing while task_struct stayed where it should be. At one point, there
>> were 127 task_structs and 3530 mm_structs.
>>
>> I am still trying to figure out what is going on here, but I thought I might
>> throw this out there to see if anyone else has seen anything like this. And
>> possibly pointers for how to track it down. Right now I am trying to trace
>> down a possible mismatch between mmget and mmput in the process exit code. I
>> will let you know what I find.
>>
>> --Vernon
>
> I reported a similar if not the same problem against 2.6.16-rt23
> See this thread. Subject "possible 2.6.16-rt23 OOM problem"
>
> http://lkml.org/lkml/2006/5/25/239
>
> I found a way around the problem so didn't pursue it. Maybe "my way around it"
> might help in tracking it down.
>
> Mark
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>

See this one instead. Its my own follow up.

http://lkml.org/lkml/2006/6/7/58

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