Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756650AbZJVPtL (ORCPT ); Thu, 22 Oct 2009 11:49:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756526AbZJVPtK (ORCPT ); Thu, 22 Oct 2009 11:49:10 -0400 Received: from gir.skynet.ie ([193.1.99.77]:44653 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756512AbZJVPtI (ORCPT ); Thu, 22 Oct 2009 11:49:08 -0400 Date: Thu, 22 Oct 2009 16:49:13 +0100 From: Mel Gorman To: Pekka Enberg Cc: Frans Pop , Jiri Kosina , Sven Geggus , Karol Lewandowski , Tobias Oetiker , "Rafael J. Wysocki" , David Miller , Reinette Chatre , Kalle Valo , David Rientjes , KOSAKI Motohiro , Mohamed Abbas , Jens Axboe , "John W. Linville" , Bartlomiej Zolnierkiewicz , Greg Kroah-Hartman , Stephan von Krawczynski , Kernel Testers List , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "linux-mm@kvack.org" Subject: Re: [PATCH 1/5] page allocator: Always wake kswapd when restarting an allocation attempt after direct reclaim failed Message-ID: <20091022154913.GQ11778@csn.ul.ie> References: <1256221356-26049-1-git-send-email-mel@csn.ul.ie> <1256221356-26049-2-git-send-email-mel@csn.ul.ie> <84144f020910220741o51c7e3dajcfd7b78d6dbbc4eb@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <84144f020910220741o51c7e3dajcfd7b78d6dbbc4eb@mail.gmail.com> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2496 Lines: 60 On Thu, Oct 22, 2009 at 05:41:53PM +0300, Pekka Enberg wrote: > On Thu, Oct 22, 2009 at 5:22 PM, Mel Gorman wrote: > > 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 > > application 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 > > You seem to have dropped the Reviewed-by tags from me and Christoph > for this patch. > My apologies. I missed then when going through the old mails. > > ?mm/page_alloc.c | ? ?2 +- > > ?1 files changed, 1 insertions(+), 1 deletions(-) > > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index bf72055..dfa4362 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -1817,9 +1817,9 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, > > ? ? ? ?if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) > > ? ? ? ? ? ? ? ?goto nopage; > > > > +restart: > > ? ? ? ?wake_all_kswapd(order, zonelist, high_zoneidx); > > > > -restart: > > ? ? ? ?/* > > ? ? ? ? * OK, we're below the kswapd watermark and have kicked background > > ? ? ? ? * reclaim. Now things get more complex, so set up alloc_flags according > > -- > > 1.6.3.3 > > > > -- > > To unsubscribe, send a message with 'unsubscribe linux-mm' in > > the body to majordomo@kvack.org. ?For more info on Linux MM, > > see: http://www.linux-mm.org/ . > > Don't email: email@kvack.org > > > -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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/