Re: [PATCH 1/3] mm: slub: Do not wake kswapd for SLUBs speculative high-order allocations

David Rientjes
2011-05-11T20:38:50Z

On Wed, 11 May 2011, Mel Gorman wrote:

> To avoid locking and per-cpu overhead, SLUB optimisically uses
> high-order allocations and falls back to lower allocations if they
> fail. However, by simply trying to allocate, kswapd is woken up to
> start reclaiming at that order. On a desktop system, two users report
> that the system is getting locked up with kswapd using large amounts
> of CPU. Using SLAB instead of SLUB made this problem go away.
>
> This patch prevents kswapd being woken up for high-order allocations.
> Testing indicated that with this patch applied, the system was much
> harder to hang and even when it did, it eventually recovered.
>
> Signed-off-by: Mel Gorman <mgorman@suse.de>

Acked-by: David Rientjes <rientjes@google.com>