| Message ID | 1305127773-10570-2-git-send-email-mgorman@suse.de |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
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> -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/mm/slub.c b/mm/slub.c index 9d2e5e4..98c358d 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1170,7 +1170,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) * Let the initial higher-order allocation fail under memory pressure * so we fall-back to the minimum order allocation. */ - alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL; + alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY | __GFP_NO_KSWAPD) & ~__GFP_NOFAIL; page = alloc_slab_page(alloc_gfp, node, oo); if (unlikely(!page)) {
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> --- mm/slub.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)