From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pekka Enberg Subject: Re: [PATCH 1/5] page allocator: Always wake kswapd when restarting an allocation attempt after direct reclaim failed Date: Thu, 22 Oct 2009 17:41:53 +0300 Message-ID: <84144f020910220741o51c7e3dajcfd7b78d6dbbc4eb@mail.gmail.com> References: <1256221356-26049-1-git-send-email-mel@csn.ul.ie> <1256221356-26049-2-git-send-email-mel@csn.ul.ie> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to:cc :content-type:content-transfer-encoding; bh=C/BpqNUKciuVmEyaUq7J/eqC6aGROgUPBhhj2c28yXE=; b=NIxByAME9LECced1IPKkEEXoMPImfEVAf9mziWYtISMhEaDW5y8r71FYaxpWILfuLJ fnPtKPhqA2gRhc7OFi6aP7X3gO+7dHMn1oLIGQ93Vkmt9LVu1RZn5hBXY2Gu4f03F9FW Oax9jlDUOopEwPv+bUGYUDW2wIXhbfYaKoIA8= In-Reply-To: <1256221356-26049-2-git-send-email-mel@csn.ul.ie> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="iso-8859-1" To: Mel Gorman 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\"" On Thu, Oct 22, 2009 at 5:22 PM, Mel Gorman wrote: > If a direct reclaim makes no forward progress, it considers whether i= t > should go OOM or not. Whether OOM is triggered or not, it may retry t= he > 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 previo= usly. > > 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, b= ut > 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. > =A0mm/page_alloc.c | =A0 =A02 +- > =A01 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, > =A0 =A0 =A0 =A0if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) =3D=3D GFP= _THISNODE) > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0goto nopage; > > +restart: > =A0 =A0 =A0 =A0wake_all_kswapd(order, zonelist, high_zoneidx); > > -restart: > =A0 =A0 =A0 =A0/* > =A0 =A0 =A0 =A0 * OK, we're below the kswapd watermark and have kicke= d background > =A0 =A0 =A0 =A0 * reclaim. Now things get more complex, so set up all= oc_flags according > -- > 1.6.3.3 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. =A0For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org >