Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756678Ab0DWIpa (ORCPT ); Fri, 23 Apr 2010 04:45:30 -0400 Received: from smtp-out.google.com ([216.239.44.51]:57385 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755338Ab0DWIp1 (ORCPT ); Fri, 23 Apr 2010 04:45:27 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id: references:user-agent:mime-version:content-type:x-system-of-record; b=o13ntP5zh2CMgyK4oYwqRZpB/dc0secTHwvUlLB6+KVWcrhDgCN4k2Au4DKthtYL1 7NMfeD9R3RYf72Eo4b32g== Date: Fri, 23 Apr 2010 01:45:17 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Miao Xie cc: Lee Schermerhorn , Nick Piggin , Paul Menage , Andrew Morton , Linux-Kernel , Linux-MM Subject: Re: [PATCH 1/2] mm: fix bugs of mpol_rebind_nodemask() In-Reply-To: <4BD0F797.6020704@cn.fujitsu.com> Message-ID: References: <4BD05929.8040900@cn.fujitsu.com> <4BD0F797.6020704@cn.fujitsu.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1004 Lines: 22 On Fri, 23 Apr 2010, Miao Xie wrote: > Suppose the current mempolicy nodes is 0-2, we can remap it from 0-2 to 2, > then we can remap it from 2 to 1, but we can't remap it from 2 to 0-2. > > that is to say it can't be remaped to a large set of allowed nodes, and the task > just can use the small set of nodes for ever, even the large set of nodes is allowed, > I think it is unreasonable. > That's been the behavior for at least three years so changing it from under the applications isn't acceptable, see Documentation/vm/numa_memory_policy.txt regarding mempolicy rebinds and the two flags that are defined that can be used to adjust the behavior. The pol->v.nodes = nodes_empty(tmp) ? *nodes : tmp fix is welcome, however, as a standalone patch. -- 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/