Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758475AbZLGANJ (ORCPT ); Sun, 6 Dec 2009 19:13:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758452AbZLGANF (ORCPT ); Sun, 6 Dec 2009 19:13:05 -0500 Received: from kroah.org ([198.145.64.141]:34337 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758403AbZLGAM5 (ORCPT ); Sun, 6 Dec 2009 19:12:57 -0500 X-Mailbox-Line: From gregkh@mini.kroah.org Sun Dec 6 16:06:46 2009 Message-Id: <20091207000646.474598476@mini.kroah.org> User-Agent: quilt/0.48-1 Date: Sun, 06 Dec 2009 16:00:14 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Mel Gorman Subject: [038/119] page allocator: always wake kswapd when restarting an allocation attempt after direct reclaim failed References: <20091206235936.208334321@mini.kroah.org> Content-Disposition: inline; filename=page-allocator-always-wake-kswapd-when-restarting-an-allocation-attempt-after-direct-reclaim-failed.patch In-Reply-To: <20091207000938.GA24743@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2228 Lines: 49 2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: Mel Gorman commit cc4a6851466039a8a688c843962a05689059ff3b upstream. If a direct reclaim makes no forward progress, it considers whether it should go OOM or not. Whether OOM is triggered or not, it may retry the allocation afterwards. In times past, this would always wake kswapd as well but currently, kswapd is not woken up after direct reclaim fails. For order-0 allocations, this makes little difference but if there is a heavy mix of higher-order allocations that direct reclaim is failing for, it might mean that kswapd is not rewoken for higher orders as much as it did previously. This patch wakes up kswapd when an allocation is being retried after a direct reclaim failure. It would be expected that kswapd is already awake, but this has the effect of telling kswapd to reclaim at the higher order as well. Signed-off-by: Mel Gorman Reviewed-by: Christoph Lameter Reviewed-by: Pekka Enberg Reviewed-by: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1763,6 +1763,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, u if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) goto nopage; +restart: wake_all_kswapd(order, zonelist, high_zoneidx); /* @@ -1772,7 +1773,6 @@ __alloc_pages_slowpath(gfp_t gfp_mask, u */ alloc_flags = gfp_to_alloc_flags(gfp_mask); -restart: /* This is the last chance, in general, before the goto nopage. */ page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, high_zoneidx, alloc_flags & ~ALLOC_NO_WATERMARKS, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/