Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753209Ab2KBGWV (ORCPT ); Fri, 2 Nov 2012 02:22:21 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:32273 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752343Ab2KBGWS (ORCPT ); Fri, 2 Nov 2012 02:22:18 -0400 X-IronPort-AV: E=Sophos;i="4.80,697,1344182400"; d="scan'208";a="6122863" Message-ID: <509367F5.9060801@cn.fujitsu.com> Date: Fri, 02 Nov 2012 14:28:05 +0800 From: Wen Congyang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: David Rientjes CC: 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: X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/11/02 14:21:28, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/11/02 14:21:29, Serialize complete at 2012/11/02 14:21:29 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1530 Lines: 35 At 11/01/2012 02:21 AM, 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. > Should we allow the user to bind a task to a node which has only ZONE_MOVABLE memory? Thanks Wen Congyang -- 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/