Re: 3.4-rc4 oom killer out of control.

From: Dave Jones
Date: Thu Apr 26 2012 - 17:53:02 EST


On Thu, Apr 26, 2012 at 02:40:48PM -0700, David Rientjes wrote:
> On Thu, 26 Apr 2012, Dave Jones wrote:
>
> > On a test machine that was running my system call fuzzer, I just saw
> > the oom killer take out everything but the process that was doing all
> > the memory exhausting.
> >
>
> Would it be possible to try the below patch? It should kill the thread
> using the most memory (which happens to only be a couple more megabytes on
> your system), but it might just delay the inevitable since the system is
> still in a pretty bad state.
>
> KOSAKI-san suggested doing this before and I think it's the best direction
> to go in anyway.

Sure, I'll give it a shot when I reboot.

However, see my follow-up message. I think there are two bugs here.
1) The over-aggressive oom-killer, and 2) ksmd going mental.

/sys/kernel/mm/ksm/full_scans is increasing constantly

full_scans: 146370
pages_shared: 1
pages_sharing: 4
pages_to_scan: 1250
pages_unshared: 867
pages_volatile: 1
run: 1
sleep_millisecs: 20

everything in /sys/kernel/mm/hugepages/hugepages-2048kB, is 0.

/sys/kernel/mm/transparent_hugepage/khugepaged:
alloc_sleep_millisecs 60000
defrag 1
full_scans 15
max_ptes_none 511
pages_collapsed 6
pages_to_scan 4096
scan_sleep_millisecs 10000


Dave

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