From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 2EFFD8D0039 for ; Tue, 22 Feb 2011 09:55:20 -0500 (EST) Date: Tue, 22 Feb 2011 15:54:50 +0100 From: Andrea Arcangeli Subject: Re: too big min_free_kbytes Message-ID: <20110222145450.GA13092@random.random> References: <20110126154203.GS926@random.random> <20110126163655.GU18984@csn.ul.ie> <20110126174236.GV18984@csn.ul.ie> <20110127134057.GA32039@csn.ul.ie> <20110127152755.GB30919@random.random> <20110203025808.GJ5843@random.random> <20110214022524.GA18198@sli10-conroe.sh.intel.com> <20110222142559.GD15652@csn.ul.ie> <20110222144200.GY13092@random.random> <20110222145030.GE15652@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110222145030.GE15652@csn.ul.ie> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Shaohua Li , Andrew Morton , linux-mm , "Chen, Tim C" , Rik van Riel , alex.shi@intel.com On Tue, Feb 22, 2011 at 02:50:31PM +0000, Mel Gorman wrote: > For workloads that cause a lot of fragmentation - yes. Simplistically with 1, > the trace event mm_page_alloc_extfrag will trigger more frequently and > it's more likely to be severe. The problem is that if it's not "* 2", > there is a very low probability that there will pages free in a suitable > pageblock and "mixing" occurs. It can take a very long time for > allocation success rates to go down but it happens eventually. Ok I see. Thanks for the clarification. So I think the other two spots I quoted in prev email are the only two bits we can adjust if booting madvise doesn't fix it completely (in addition to the *8 removal in kswapd, but that only affects ~4G systems, that are however very common this is an old bug that just got better exposed with an higher min_free_kbytes default). -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org