From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta12.messagelabs.com (mail6.bemta12.messagelabs.com [216.82.250.247]) by kanga.kvack.org (Postfix) with ESMTP id 41F566B004A for ; Thu, 14 Jul 2011 00:46:53 -0400 (EDT) Date: Thu, 14 Jul 2011 00:46:43 -0400 From: Christoph Hellwig Subject: Re: [PATCH 1/5] mm: vmscan: Do not writeback filesystem pages in direct reclaim Message-ID: <20110714044643.GA3203@infradead.org> References: <1310567487-15367-1-git-send-email-mgorman@suse.de> <1310567487-15367-2-git-send-email-mgorman@suse.de> <20110714103801.83e10fdb.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110714103801.83e10fdb.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: Mel Gorman , Linux-MM , LKML , XFS , Dave Chinner , Christoph Hellwig , Johannes Weiner , Wu Fengguang , Jan Kara , Rik van Riel , Minchan Kim On Thu, Jul 14, 2011 at 10:38:01AM +0900, KAMEZAWA Hiroyuki wrote: > > + /* > > + * Only kswapd can writeback filesystem pages to > > + * avoid risk of stack overflow > > + */ > > + if (page_is_file_cache(page) && !current_is_kswapd()) { > > + inc_zone_page_state(page, NR_VMSCAN_WRITE_SKIP); > > + goto keep_locked; > > + } > > + > > > This will cause tons of memcg OOM kill because we have no help of kswapd (now). XFS and btrfs already disable writeback from memcg context, as does ext4 for the typical non-overwrite workloads, and none has fallen apart. In fact there's no way we can enable them as the memcg calling contexts tend to have massive stack usage. -- 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