Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754954AbZJPKwt (ORCPT ); Fri, 16 Oct 2009 06:52:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751616AbZJPKwt (ORCPT ); Fri, 16 Oct 2009 06:52:49 -0400 Received: from mail-fx0-f218.google.com ([209.85.220.218]:39723 "EHLO mail-fx0-f218.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751142AbZJPKws convert rfc822-to-8bit (ORCPT ); Fri, 16 Oct 2009 06:52:48 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=OewgOfqyup4SBT4SzxOuQ2p19OY1C5qtmWj1/C7TCazBsG0G7u1nVhl27oL+/TywzY M4O3apuoWjSfGUoD06//WXPMK3fPY5WlQLqEOmuKCTbKjCKaJb8RH66ZA+ukKCgkH4gY nbevPL1pfHqCqvHCc3pY53+AUtQ5Xtoy1SD/w= MIME-Version: 1.0 In-Reply-To: <1255689446-3858-2-git-send-email-mel@csn.ul.ie> References: <1255689446-3858-1-git-send-email-mel@csn.ul.ie> <1255689446-3858-2-git-send-email-mel@csn.ul.ie> Date: Fri, 16 Oct 2009 13:52:09 +0300 X-Google-Sender-Auth: fb7d1fca61eebb1d Message-ID: <84144f020910160352n3a334e84hd248b78e0093716d@mail.gmail.com> Subject: Re: [PATCH 1/2] page allocator: Always wake kswapd when restarting an allocation attempt after direct reclaim failed From: Pekka Enberg To: Mel Gorman Cc: Andrew Morton , stable , "Rafael J. Wysocki" , David Miller , Frans Pop , reinette chatre , Kalle Valo , "John W. Linville" , Bartlomiej Zolnierkiewicz , Karol Lewandowski , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "linux-mm@kvack.org\"" Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2092 Lines: 50 On Fri, Oct 16, 2009 at 1:37 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 Reviewed-by: Pekka Enberg > --- > ?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 > -- 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/