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 ESMTP id 8E0E96B016A for ; Mon, 8 Aug 2011 20:12:17 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp (unknown [10.0.50.72]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 554073EE0BD for ; Tue, 9 Aug 2011 09:12:14 +0900 (JST) Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 3A8D445DE8A for ; Tue, 9 Aug 2011 09:12:14 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 1D74645DE7E for ; Tue, 9 Aug 2011 09:12:14 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 0F19D1DB803E for ; Tue, 9 Aug 2011 09:12:14 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.240.81.134]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id CB9571DB802C for ; Tue, 9 Aug 2011 09:12:13 +0900 (JST) Date: Tue, 9 Aug 2011 09:04:55 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 2/2] vmscan: activate executable pages after first usage Message-Id: <20110809090455.92901845.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: <20110808110658.31053.55013.stgit@localhost6> <20110808110659.31053.92935.stgit@localhost6> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Konstantin Khlebnikov , linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, Wu Fengguang , Johannes Weiner On Tue, 9 Aug 2011 09:02:28 +0900 Minchan Kim wrote: > On Mon, Aug 8, 2011 at 8:07 PM, Konstantin Khlebnikov > wrote: > > Logic added in commit v2.6.30-5507-g8cab475 > > (vmscan: make mapped executable pages the first class citizen) > > was noticeably weakened in commit v2.6.33-5448-g6457474 > > (vmscan: detect mapped file pages used only once) > > > > Currently these pages can become "first class citizens" only after second usage. > > > > After this patch page_check_references() will activate they after first usage, > > and executable code gets yet better chance to stay in memory. > > > > TODO: > > run some cool tests like in v2.6.30-5507-g8cab475 =) > > > > Signed-off-by: Konstantin Khlebnikov > > --- > > It might be a very controversial topic. > AFAIR, at least, we did when vmscan: make mapped executable pages the > first class citizen was merged. :) > > You try to change behavior. > > Old : protect *working set* executable page > New: protect executable page *unconditionally*. > Hmm ? I thought Old: protect pages if referenced twice New: protect executable page if referenced once. IIUC, ANON is proteced if it's referenced once. So, this patch changes EXECUTABLE file to the same class as ANON pages. Anyway, I agree test/measurement is required. Thanks, -Kame -- 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