From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id CC6786B007B for ; Thu, 2 Jun 2011 11:54:43 -0400 (EDT) Received: by bwz17 with SMTP id 17so1659563bwz.14 for ; Thu, 02 Jun 2011 08:54:39 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20110602142408.GB28684@cmpxchg.org> References: <1306909519-7286-1-git-send-email-hannes@cmpxchg.org> <1306909519-7286-9-git-send-email-hannes@cmpxchg.org> <20110602142408.GB28684@cmpxchg.org> Date: Fri, 3 Jun 2011 00:54:39 +0900 Message-ID: Subject: Re: [patch 8/8] mm: make per-memcg lru lists exclusive From: Hiroyuki Kamezawa Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: KAMEZAWA Hiroyuki , Daisuke Nishimura , Balbir Singh , Ying Han , Michal Hocko , Andrew Morton , Rik van Riel , Minchan Kim , KOSAKI Motohiro , Mel Gorman , Greg Thelen , Michel Lespinasse , linux-mm@kvack.org, linux-kernel@vger.kernel.org 2011/6/2 Johannes Weiner : > On Thu, Jun 02, 2011 at 10:16:59PM +0900, Hiroyuki Kamezawa wrote: >> 2011/6/1 Johannes Weiner : >> > All lru list walkers have been converted to operate on per-memcg >> > lists, the global per-zone lists are no longer required. >> > >> > This patch makes the per-memcg lists exclusive and removes the global >> > lists from memcg-enabled kernels. >> > >> > The per-memcg lists now string up page descriptors directly, which >> > unifies/simplifies the list isolation code of page reclaim as well as >> > it saves a full double-linked list head for each page in the system. >> > >> > At the core of this change is the introduction of the lruvec >> > structure, an array of all lru list heads. =A0It exists for each zone >> > globally, and for each zone per memcg. =A0All lru list operations are >> > now done in generic code against lruvecs, with the memcg lru list >> > primitives only doing accounting and returning the proper lruvec for >> > the currently scanned memcg on isolation, or for the respective page >> > on putback. >> > >> > Signed-off-by: Johannes Weiner >> >> >> could you divide this into >> =A0 - introduce lruvec >> =A0 - don't record section? information into pc->flags because we see >> "page" on memcg LRU >> =A0 =A0 and there is no requirement to get page from "pc". >> =A0 - remove pc->lru completely > > Yes, that makes sense. =A0It shall be fixed in the next version. > BTW, IIUC, Transparent hugepage has a code to link a page to the page->lru directly. And recent Minchan's work does the same kind of trick. But it may put a page onto wrong memcgs if we do link a page to another page's page->lru because 2 pages may be in different cgroup each other. Could you check there are more codes which does link page->lru to nearby pa= ge's page->lru ? Now, I'm not sure there are other codes....but we need care. 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