From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 846296B0169 for ; Mon, 8 Aug 2011 20:02:30 -0400 (EDT) Received: by qyk7 with SMTP id 7so3195370qyk.14 for ; Mon, 08 Aug 2011 17:02:28 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20110808110659.31053.92935.stgit@localhost6> References: <20110808110658.31053.55013.stgit@localhost6> <20110808110659.31053.92935.stgit@localhost6> Date: Tue, 9 Aug 2011 09:02:28 +0900 Message-ID: Subject: Re: [PATCH 2/2] vmscan: activate executable pages after first usage From: Minchan Kim Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Konstantin Khlebnikov Cc: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, Wu Fengguang , KAMEZAWA Hiroyuki , Johannes Weiner 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*. At least, old logic can ignore some executable pages which are not accessed recently. Wu had many testing to persuade others. As you said, we need some number to change policy. -- Kind regards, Minchan Kim -- 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