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 ESMTP id E27B08D0041 for ; Thu, 24 Mar 2011 01:35:13 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 2E3C43EE0BD for ; Thu, 24 Mar 2011 14:35:09 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id EEF1D45DE5A for ; Thu, 24 Mar 2011 14:35:08 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id D30A345DE5C for ; Thu, 24 Mar 2011 14:35:08 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id BE0331DB804D for ; Thu, 24 Mar 2011 14:35:08 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.240.81.146]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 70B36E08003 for ; Thu, 24 Mar 2011 14:35:08 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 1/5] vmscan: remove all_unreclaimable check from direct reclaim path completely In-Reply-To: <20110323200458.724f2af8.akpm@linux-foundation.org> References: <20110324114842.CC70.A69D9226@jp.fujitsu.com> <20110323200458.724f2af8.akpm@linux-foundation.org> Message-Id: <20110324143541.CC77.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Date: Thu, 24 Mar 2011 14:35:07 +0900 (JST) Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: kosaki.motohiro@jp.fujitsu.com, Minchan Kim , linux-kernel@vger.kernel.org, David Rientjes , Linus Torvalds , Rik van Riel , Oleg Nesterov , linux-mm , Andrey Vagin , Hugh Dickins , KAMEZAWA Hiroyuki , Nick Piggin , Johannes Weiner > On Thu, 24 Mar 2011 11:48:19 +0900 (JST) KOSAKI Motohiro wrote: > > > > On Thu, 24 Mar 2011 11:11:46 +0900 (JST) KOSAKI Motohiro wrote: > > > > > > > Subject: [PATCH] vmscan: remove all_unreclaimable check from direct reclaim path completely > > > > > > zone.all_unreclaimable is there to prevent reclaim from wasting CPU > > > cycles scanning a zone which has no reclaimable pages. When originally > > > implemented it did this very well. > > > > > > That you guys keep breaking it, or don't feel like improving it is not a > > > reason to remove it! > > > > > > If the code is unneeded and the kernel now reliably solves this problem > > > by other means then this should have been fully explained in the > > > changelog, but it was not even mentioned. > > > > The changelog says, the logic was removed at 2008. three years ago. > > even though it's unintentionally. and I and minchan tried to resurrect > > the broken logic and resurrected a bug in the logic too. then, we > > are discussed it should die or alive. > > > > Which part is hard to understand for you? > > The part which isn't there: how does the kernel now address the problem > which that code fixed? Ah, got it. The history says the problem haven't occur for three years. thus I meant past: code exist, but broken and don't work for three years. new: code removed. What's different? But last minchan's mail pointed out recent drain_all_pages() stuff depend on a return value of try_to_free_pages. thus, I've made new patch and sent it. please see it? -- 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