Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753005Ab2KBGFj (ORCPT ); Fri, 2 Nov 2012 02:05:39 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:36651 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751300Ab2KBGFf (ORCPT ); Fri, 2 Nov 2012 02:05:35 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.8.4 Message-ID: <50936288.5090008@jp.fujitsu.com> Date: Fri, 02 Nov 2012 15:04:56 +0900 From: Kamezawa Hiroyuki User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:16.0) Gecko/20121026 Thunderbird/16.0.2 MIME-Version: 1.0 To: David Rientjes CC: Wen Congyang , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, Rob Landley , Andrew Morton , Yasuaki Ishimatsu , Lai Jiangshan , Jiang Liu , KOSAKI Motohiro , Minchan Kim , Mel Gorman , Yinghai Lu , "rusty@rustcorp.com.au" Subject: Re: [PART6 Patch] mempolicy: fix is_valid_nodemask() References: <1351675458-11859-1-git-send-email-wency@cn.fujitsu.com> <1351675458-11859-2-git-send-email-wency@cn.fujitsu.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1575 Lines: 41 (2012/11/01 3:21), David Rientjes wrote: > On Wed, 31 Oct 2012, Wen Congyang wrote: > >> From: Lai Jiangshan >> >> is_valid_nodemask() is introduced by 19770b32. but it does not match >> its comments, because it does not check the zone which > policy_zone. >> >> Also in b377fd, this commits told us, if highest zone is ZONE_MOVABLE, >> we should also apply memory policies to it. so ZONE_MOVABLE should be valid zone >> for policies. is_valid_nodemask() need to be changed to match it. >> >> Fix: check all zones, even its zoneid > policy_zone. >> Use nodes_intersects() instead open code to check it. >> > > This changes the semantics of MPOL_BIND to be considerably different than > what it is today: slab allocations are no longer bound by such a policy > which isn't consistent with what userspace expects or is specified by > set_mempolicy() and there's no way, with your patch, to actually specify > that we don't care about ZONE_MOVABLE and that the slab allocations > _should_ actually be allocated on movable-only zones. You have to respect > cases where people aren't interested in node hotplug and not cause a > regression. > I'm sorry if I misunderstand somehing.... I think people doesn't insterested in node-hotplug will never have MOVABLE_ZONE. What causes regression ? Thanks, -Kame -- 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/