From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f175.google.com (mail-pd0-f175.google.com [209.85.192.175]) by kanga.kvack.org (Postfix) with ESMTP id EF30C6B0035 for ; Fri, 11 Apr 2014 06:54:58 -0400 (EDT) Received: by mail-pd0-f175.google.com with SMTP id x10so5098553pdj.6 for ; Fri, 11 Apr 2014 03:54:57 -0700 (PDT) Received: from mail-pd0-x233.google.com (mail-pd0-x233.google.com [2607:f8b0:400e:c02::233]) by mx.google.com with ESMTPS id ov9si2658723pbc.256.2014.04.11.03.54.56 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 11 Apr 2014 03:54:56 -0700 (PDT) Received: by mail-pd0-f179.google.com with SMTP id w10so5150710pde.38 for ; Fri, 11 Apr 2014 03:54:56 -0700 (PDT) Date: Fri, 11 Apr 2014 03:54:53 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH 1/1] doc, mempolicy: Fix wrong document in numa_memory_policy.txt In-Reply-To: <5347280B.3000303@infradead.org> Message-ID: References: <1396410782-26208-1-git-send-email-tangchen@cn.fujitsu.com> <5347280B.3000303@infradead.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Randy Dunlap Cc: Tang Chen , hannes@cmpxchg.org, mhocko@suse.cz, bsingharora@gmail.com, kamezawa.hiroyu@jp.fujitsu.com, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, guz.fnst@cn.fujitsu.com, Andrew Morton On Thu, 10 Apr 2014, Randy Dunlap wrote: > On 04/01/2014 08:53 PM, Tang Chen wrote: > > In document numa_memory_policy.txt, the following examples for flag > > MPOL_F_RELATIVE_NODES are incorrect. > > > > For example, consider a task that is attached to a cpuset with > > mems 2-5 that sets an Interleave policy over the same set with > > MPOL_F_RELATIVE_NODES. If the cpuset's mems change to 3-7, the > > interleave now occurs over nodes 3,5-6. If the cpuset's mems > > then change to 0,2-3,5, then the interleave occurs over nodes > > 0,3,5. > > > > According to the comment of the patch adding flag MPOL_F_RELATIVE_NODES, > > the nodemasks the user specifies should be considered relative to the > > current task's mems_allowed. > > (https://lkml.org/lkml/2008/2/29/428) > > > > And according to numa_memory_policy.txt, if the user's nodemask includes > > nodes that are outside the range of the new set of allowed nodes, then > > the remap wraps around to the beginning of the nodemask and, if not already > > set, sets the node in the mempolicy nodemask. > > > > So in the example, if the user specifies 2-5, for a task whose mems_allowed > > is 3-7, the nodemasks should be remapped the third, fourth, fifth, sixth > > node in mems_allowed. like the following: > > > > mems_allowed: 3 4 5 6 7 > > > > relative index: 0 1 2 3 4 > > 5 > > > > So the nodemasks should be remapped to 3,5-7, but not 3,5-6. > > > > And for a task whose mems_allowed is 0,2-3,5, the nodemasks should be > > remapped to 0,2-3,5, but not 0,3,5. > > > > mems_allowed: 0 2 3 5 > > > > relative index: 0 1 2 3 > > 4 5 > > > > > > Signed-off-by: Tang Chen > > Wow. This was not an April fools joke, right? > It would have been a horrible joke if it was intended to be :) > Have there been any acks of this? I haven't seen any responses to it. > Because everybody in the phonebook was cc'd on it except for the author who wrote it. Tang, good catch. Acked-by: David Rientjes -- 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