Re: + mm-invoke-oom-killer-from-page-fault.patch added to -mm tree

From: Ingo Molnar
Date: Wed Oct 22 2008 - 02:28:36 EST

* akpm@xxxxxxxxxxxxxxxxxxxx <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> The patch titled
> mm: invoke oom-killer from page fault
> has been added to the -mm tree. Its filename is
> mm-invoke-oom-killer-from-page-fault.patch
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> ------------------------------------------------------
> Subject: mm: invoke oom-killer from page fault
> From: Nick Piggin <npiggin@xxxxxxx>
> Rather than have the pagefault handler kill a process directly if it gets
> a VM_FAULT_OOM, have it call into the OOM killer.
> With increasingly sophisticated oom behaviour (cpusets, memory cgroups,
> oom killing throttling, oom priority adjustment or selective disabling,
> panic on oom, etc), it's silly to unconditionally kill the faulting
> process at page fault time. Create a hook for pagefault oom path to call
> into instead.
> Only converted x86 and uml so far.
> Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
> Cc: Jeff Dike <jdike@xxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

the x86 bits look sane in principle. Needs a lot of testing obviously.

Acked-by: Ingo Molnar <mingo@xxxxxxx>

a small nit:

> + /*
> + * Give "p" a good chance of killing itself before we
> + * retry to allocate memory unless "p" is current
> + */
> + if (!test_thread_flag(TIF_MEMDIE))
> + schedule_timeout_uninterruptible(1);

comment does not match up the code anymore, we only deal with 'current'

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