From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 404FB6B006A for ; Mon, 2 Nov 2009 12:33:01 -0500 (EST) From: Frans Pop Subject: Re: [PATCH 3/3] vmscan: Force kswapd to take notice faster when high-order watermarks are being hit Date: Mon, 2 Nov 2009 18:32:54 +0100 References: <1256650833-15516-1-git-send-email-mel@csn.ul.ie> <20091028124756.7af44b6b.akpm@linux-foundation.org> <20091102160534.GA22046@csn.ul.ie> In-Reply-To: <20091102160534.GA22046@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200911021832.59035.elendil@planet.nl> Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: Andrew Morton , stable@kernel.org, linux-kernel@vger.kernel.org, "linux-mm@kvack.org" , Jiri Kosina , Sven Geggus , Karol Lewandowski , Tobias Oetiker , KOSAKI Motohiro , Pekka Enberg , Rik van Riel , Christoph Lameter , Stephan von Krawczynski , Kernel Testers List List-ID: On Monday 02 November 2009, Mel Gorman wrote: > vmscan: Help debug kswapd issues by counting number of rewakeups and > premature sleeps > > There is a growing amount of anedotal evidence that high-order atomic > allocation failures have been increasing since 2.6.31-rc1. The two > strongest possibilities are a marked increase in the number of > GFP_ATOMIC allocations and alterations in timing. Debugging printk > patches have shown for example that kswapd is sleeping for shorter > intervals and going to sleep when watermarks are still not being met. > > This patch adds two kswapd counters to help identify if timing is an > issue. The first counter kswapd_highorder_rewakeup counts the number of > times that kswapd stops reclaiming at one order and restarts at a higher > order. The second counter kswapd_slept_prematurely counts the number of > times kswapd went to sleep when the high watermark was not met. What testing would you like done with this patch? -- 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