From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id CF0796B006E for ; Thu, 10 Nov 2011 11:14:28 -0500 (EST) Date: Thu, 10 Nov 2011 17:12:44 +0100 From: Johannes Weiner Subject: Re: [rfc 3/3] mm: vmscan: revert file list boost on lru addition Message-ID: <20111110161244.GN3153@redhat.com> References: <20110808110658.31053.55013.stgit@localhost6> <4E3FD403.6000400@parallels.com> <20111102163056.GG19965@redhat.com> <20111102163247.GJ19965@redhat.com> <20111107114520.33050d75.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111107114520.33050d75.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: Konstantin Khlebnikov , Pekka Enberg , "linux-mm@kvack.org" , Andrew Morton , "linux-kernel@vger.kernel.org" , Wu Fengguang , Johannes Weiner , Rik van Riel , Mel Gorman , Minchan Kim , Gene Heskett On Mon, Nov 07, 2011 at 11:45:20AM +0900, KAMEZAWA Hiroyuki wrote: > On Wed, 2 Nov 2011 17:32:47 +0100 > Johannes Weiner wrote: > > > The idea in 9ff473b 'vmscan: evict streaming IO first' was to steer > > reclaim focus onto file pages with every new file page that hits the > > lru list, so that an influx of used-once file pages does not lead to > > swapping of anonymous pages. > > > > The problem is that nobody is fixing up the balance if the pages in > > fact become part of the resident set. > > > > Anonymous page creation is neutral to the inter-lru balance, so even a > > comparably tiny number of heavily used file pages tip the balance in > > favor of the file list. > > > > In addition, there is no refault detection, and every refault will > > bias the balance even more. A thrashing file working set will be > > mistaken for a very lucrative source of reclaimable pages. > > > > As anonymous pages are no longer swapped above a certain priority > > level, this mechanism is no longer needed. Used-once file pages > > should get reclaimed before the VM even considers swapping. > > > > Signed-off-by: Johannes Weiner > > Do you have some results ? Not yet, sorry, I had to drop it all and do something else. This change relies on the VM having a different mechanism to go for one-shot file cache first, so I need to address Kosaki-san's concerns about 1/3 before pursuing 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org