From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id AC7EE6B024A for ; Tue, 6 Jul 2010 16:28:32 -0400 (EDT) Date: Tue, 6 Jul 2010 22:27:58 +0200 From: Johannes Weiner Subject: Re: [PATCH 12/14] vmscan: Do not writeback pages in direct reclaim Message-ID: <20100706202758.GC18210@cmpxchg.org> References: <20100702125155.69c02f85.akpm@linux-foundation.org> <20100705134949.GC13780@csn.ul.ie> <20100706093529.CCD1.A69D9226@jp.fujitsu.com> <20100706101235.GE13780@csn.ul.ie> <20100706152539.GG13780@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100706152539.GG13780@csn.ul.ie> Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: Minchan Kim , KOSAKI Motohiro , Andrew Morton , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Chris Mason , Nick Piggin , Rik van Riel , Christoph Hellwig , KAMEZAWA Hiroyuki , Andrea Arcangeli List-ID: On Tue, Jul 06, 2010 at 04:25:39PM +0100, Mel Gorman wrote: > On Tue, Jul 06, 2010 at 08:24:57PM +0900, Minchan Kim wrote: > > but it is still problem in case of swap file. > > That's because swapout on swapfile cause file system writepage which > > makes kernel stack overflow. > > I don't *think* this is a problem unless I missed where writing out to > swap enters teh filesystem code. I'll double check. It bypasses the fs. On swapon, the blocks are resolved (mm/swapfile.c::setup_swap_extents) and then the writeout path uses bios directly (mm/page_io.c::swap_writepage). (GFP_NOFS still includes __GFP_IO, so allows swapping) Hannes -- 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