From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 1D17E6B004F for ; Sun, 12 Jul 2009 22:48:26 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n6D38F2s010303 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Mon, 13 Jul 2009 12:08:15 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 6B3B145DE50 for ; Mon, 13 Jul 2009 12:08:15 +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 4CBB745DE4F for ; Mon, 13 Jul 2009 12:08:15 +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 329B2E08001 for ; Mon, 13 Jul 2009 12:08:15 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id E0FF41DB8040 for ; Mon, 13 Jul 2009 12:08:14 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH] switch free memory back to MIGRATE_MOVABLE In-Reply-To: <20090713030444.GA2582@sli10-desk.sh.intel.com> References: <20090713115803.b78a4f4f.kamezawa.hiroyu@jp.fujitsu.com> <20090713030444.GA2582@sli10-desk.sh.intel.com> Message-Id: <20090713120549.6252.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Mon, 13 Jul 2009 12:08:14 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Shaohua Li Cc: kosaki.motohiro@jp.fujitsu.com, KAMEZAWA Hiroyuki , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "mel@csn.ul.ie" , "akpm@linux-foundation.org" List-ID: > On Mon, Jul 13, 2009 at 10:58:03AM +0800, KAMEZAWA Hiroyuki wrote: > > On Mon, 13 Jul 2009 11:47:46 +0900 (JST) > > KOSAKI Motohiro wrote: > > > > > > When page is back to buddy and its order is bigger than pageblock_order, we can > > > > switch its type to MIGRATE_MOVABLE. This can reduce fragmentation. The patch > > > > has obvious effect when read a block device and then drop caches. > > > > > > > > Signed-off-by: Shaohua Li > > > > > > This patch change hot path, but there is no performance mesurement description. > > > Also, I don't like modification buddy core for only drop caches. > > > > > Li, does this patch imply fallback of migration type doesn't work well ? > > What is the bad case ? > The page is initialized as migrate_movable, and then switch to reclaimable or > something else when fallback occurs, but its type remains even the page gets > freed. When the page gets freed, its type actually can be switch back to movable, > this is what the patch does. This answer is not actual answer. Why do you think __rmqueue_fallback() doesn't works well? Do you have any test-case or found a bug by review? -- 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