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

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

[Ingo Molnar]

* akpm@linux-foundation.org <akpm@linux-foundation.org> 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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> 
> *** Remember to use Documentation/SubmitChecklist when testing your code ***
> 
> See http://userweb.kernel.org/~akpm/added-to-mm.txt to find
> out what to do about this
> 
> The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
> 
> ------------------------------------------------------
> Subject: mm: invoke oom-killer from page fault
> From: Nick Piggin <npiggin@suse.de>
> 
> 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@suse.de>
> Cc: Jeff Dike <jdike@addtoit.com>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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

Acked-by: Ingo Molnar <mingo@elte.hu>

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' 
here.

	Ingo