Re: [PATCH] page-allocator: Ensure that processes that have beenOOM killed exit the page allocator (resend)

From: David Rientjes
Date: Wed Jul 15 2009 - 16:29:47 EST


On Wed, 15 Jul 2009, Mel Gorman wrote:

> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index f8902e7..5c98d02 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1547,6 +1547,14 @@ should_alloc_retry(gfp_t gfp_mask, unsigned int order,
> if (gfp_mask & __GFP_NORETRY)
> return 0;
>
> + /* Do not loop if OOM-killed unless __GFP_NOFAIL is specified */
> + if (test_thread_flag(TIF_MEMDIE)) {
> + if (gfp_mask & __GFP_NOFAIL)
> + WARN(1, "Potential infinite loop with __GFP_NOFAIL");
> + else
> + return 0;
> + }
> +
> /*
> * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER
> * means __GFP_NOFAIL, but that may not be true in other
>

This only works for GFP_ATOMIC since the next iteration of the page
allocator will (probably) fail reclaim and simply invoke the oom killer
again, which will notice current has TIF_MEMDIE set and choose to do
nothing, at which time the allocator simply loops again.
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