Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755646Ab0GFLNl (ORCPT ); Tue, 6 Jul 2010 07:13:41 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:59609 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753089Ab0GFLNk (ORCPT ); Tue, 6 Jul 2010 07:13:40 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Mel Gorman Subject: Re: [PATCH 12/14] vmscan: Do not writeback pages in direct reclaim Cc: kosaki.motohiro@jp.fujitsu.com, 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 , Johannes Weiner , Christoph Hellwig , KAMEZAWA Hiroyuki , Andrea Arcangeli In-Reply-To: <20100706101235.GE13780@csn.ul.ie> References: <20100706093529.CCD1.A69D9226@jp.fujitsu.com> <20100706101235.GE13780@csn.ul.ie> Message-Id: <20100706200310.CD06.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Tue, 6 Jul 2010 20:13:36 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1357 Lines: 40 > On Tue, Jul 06, 2010 at 09:36:41AM +0900, KOSAKI Motohiro wrote: > > Hello, > > > > > Ok, that's reasonable as I'm still working on that patch. For example, the > > > patch disabled anonymous page writeback which is unnecessary as the stack > > > usage for anon writeback is less than file writeback. > > > > How do we examine swap-on-file? > > > > Anything in particular wrong with the following? > > /* > * For now, only kswapd can writeback filesystem pages as otherwise > * there is a stack overflow risk > */ > static inline bool reclaim_can_writeback(struct scan_control *sc, > struct page *page) > { > return !page_is_file_cache(page) || current_is_kswapd(); > } > > Even if it is a swapfile, I didn't spot a case where the filesystems > writepage would be called. Did I miss something? Hmm... Now, I doubt I don't understand your mention. Do you mean you intend to swtich task stack when every writepage? It seems a bit costly. but otherwise write-page for anon makes filesystem IO and stack-overflow. Can you please elaborate your plan? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/