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 27E376B0055 for ; Sun, 22 Mar 2009 21:26:24 -0400 (EDT) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n2N2Lc6T006583 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Mon, 23 Mar 2009 11:21:39 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 1E0E245DE56 for ; Mon, 23 Mar 2009 11:21:38 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id DC0F945DE4F for ; Mon, 23 Mar 2009 11:21:37 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id A7CF8E3800A for ; Mon, 23 Mar 2009 11:21:37 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 39066E38004 for ; Mon, 23 Mar 2009 11:21:37 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [patch 3/3] mm: keep pages from unevictable mappings off the LRU lists In-Reply-To: <28c262360903221744r6d275294gdc8ad3a12b8c5361@mail.gmail.com> References: <1237752784-1989-3-git-send-email-hannes@cmpxchg.org> <28c262360903221744r6d275294gdc8ad3a12b8c5361@mail.gmail.com> Message-Id: <20090323111615.69F3.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Mon, 23 Mar 2009 11:21:36 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: kosaki.motohiro@jp.fujitsu.com, Johannes Weiner , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, David Howells , Nick Piggin , Rik van Riel , Peter Zijlstra , Lee Schermerhorn List-ID: > Hmm,, > > This patch is another thing unlike previous series patches. > Firstly, It looked good to me. > > I think add_to_page_cache_lru have to become a fast path. > But, how often would ramfs and shmem function be called ? > > I have a concern for this patch to add another burden. > so, we need any numbers for getting pros and cons. > > Any thoughts ? this is the just reason why current code don't call add_page_to_unevictable_list(). add_page_to_unevictable_list() don't use pagevec. it is needed for avoiding race. then, if readahead path (i.e. add_to_page_cache_lru()) use add_page_to_unevictable_list(), it can cause zone->lru_lock contention storm. then, if nobody have good performance result, I don't ack this patch. > On Mon, Mar 23, 2009 at 5:13 AM, Johannes Weiner wrote: > > Check if the mapping is evictable when initially adding page cache > > pages to the LRU lists. ?If that is not the case, add them to the > > unevictable list immediately instead of leaving it up to the reclaim > > code to move them there. > > > > This is useful for ramfs and locked shmem which mark whole mappings as > > unevictable and we know at fault time already that it is useless to > > try reclaiming these pages. -- 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