From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id CAF0B6B01B8 for ; Thu, 17 Jun 2010 02:28:02 -0400 (EDT) Received: from m4.gw.fujitsu.co.jp ([10.0.50.74]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o5H6S0Gl019287 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Thu, 17 Jun 2010 15:28:00 +0900 Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id A6CCB45DE7B for ; Thu, 17 Jun 2010 15:27:59 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 3E82C45DE6F for ; Thu, 17 Jun 2010 15:27:59 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id F0ED4E38009 for ; Thu, 17 Jun 2010 15:27:58 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.249.87.106]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 6C9C51DB8042 for ; Thu, 17 Jun 2010 15:27:58 +0900 (JST) Date: Thu, 17 Jun 2010 15:23:12 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 12/12] vmscan: Do not writeback pages in direct reclaim Message-Id: <20100617152312.43e84eb0.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20100617061647.GA21277@infradead.org> References: <1276514273-27693-13-git-send-email-mel@csn.ul.ie> <4C16A567.4080000@redhat.com> <20100615114510.GE26788@csn.ul.ie> <4C17815A.8080402@redhat.com> <20100615135928.GK26788@csn.ul.ie> <4C178868.2010002@redhat.com> <20100615141601.GL26788@csn.ul.ie> <20100616091755.7121c7d3.kamezawa.hiroyu@jp.fujitsu.com> <20100616050640.GA10687@infradead.org> <20100617092538.c712342b.kamezawa.hiroyu@jp.fujitsu.com> <20100617061647.GA21277@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Christoph Hellwig Cc: Mel Gorman , Rik van Riel , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Chris Mason , Nick Piggin , Johannes Weiner , Andrew Morton List-ID: On Thu, 17 Jun 2010 02:16:47 -0400 Christoph Hellwig wrote: > On Thu, Jun 17, 2010 at 09:25:38AM +0900, KAMEZAWA Hiroyuki wrote: > > > > BTW, why xbf_buf_create() use GFP_KERNEL even if it can be blocked ? > > memory cgroup just limits pages for users, then, doesn't intend to > > limit kernel pages. > > You mean xfs_buf_allocate? It doesn't in the end. It goes through the > xfs_kmem helper which clear __GFP_FS if we're currently inside a > filesystem transaction (PF_FSTRANS is set) or a caller specificly > requested it to be disabled even without that by passig the > XBF_DONT_BLOCK flag. > Ah, sorry. My question was wrong. If xfs_buf_allocate() is not for pages on LRU but for kernel memory, memory cgroup has no reason to charge against it because we can't reclaim memory which is not on LRU. Then, I wonder I may have to add following check if (!(gfp_mask & __GFP_RECLAIMABLE)) { /* ignore this. we just charge against reclaimable memory on LRU. */ return 0; } to mem_cgroup_charge_cache() which is a hook for accounting page-cache. 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/ . Don't email: email@kvack.org