From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id EFFDC6B01E3 for ; Thu, 22 Apr 2010 17:20:31 -0400 (EDT) Received: from kpbe13.cbf.corp.google.com (kpbe13.cbf.corp.google.com [172.25.105.77]) by smtp-out.google.com with ESMTP id o3MLKR9d021555 for ; Thu, 22 Apr 2010 23:20:28 +0200 Received: from pxi19 (pxi19.prod.google.com [10.243.27.19]) by kpbe13.cbf.corp.google.com with ESMTP id o3MLK3LU025851 for ; Thu, 22 Apr 2010 16:20:26 -0500 Received: by pxi19 with SMTP id 19so857542pxi.26 for ; Thu, 22 Apr 2010 14:20:26 -0700 (PDT) Date: Thu, 22 Apr 2010 14:20:23 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH 1/2] mm: fix bugs of mpol_rebind_nodemask() In-Reply-To: <4BD05929.8040900@cn.fujitsu.com> Message-ID: References: <4BD05929.8040900@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Miao Xie Cc: Lee Schermerhorn , Nick Piggin , Paul Menage , Andrew Morton , Linux-Kernel , Linux-MM List-ID: On Thu, 22 Apr 2010, Miao Xie wrote: > - local variable might be an empty nodemask, so must be checked before setting > pol->v.nodes to it. > > - nodes_remap() may cause the weight of pol->v.nodes being monotonic decreasing. > and never become large even we pass a nodemask with large weight after > ->v.nodes become little. > That's always been the intention of rebinding a mempolicy nodemask: we remap the current mempolicy nodes over the new nodemask given the set of allowed nodes. The nodes_remap() shouldn't be removed. > this patch fixes these two problem. > > Signed-off-by: Miao Xie > --- > mm/mempolicy.c | 9 ++++++--- > 1 files changed, 6 insertions(+), 3 deletions(-) > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > index 08f40a2..03ba9fc 100644 > --- a/mm/mempolicy.c > +++ b/mm/mempolicy.c > @@ -291,12 +291,15 @@ static void mpol_rebind_nodemask(struct mempolicy *pol, > else if (pol->flags & MPOL_F_RELATIVE_NODES) > mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes); > else { > - nodes_remap(tmp, pol->v.nodes, pol->w.cpuset_mems_allowed, > - *nodes); > + tmp = *nodes; > pol->w.cpuset_mems_allowed = *nodes; > } > > - pol->v.nodes = tmp; > + if (nodes_empty(tmp)) > + pol->v.nodes = *nodes; > + else > + pol->v.nodes = tmp; > + > if (!node_isset(current->il_next, tmp)) { > current->il_next = next_node(current->il_next, tmp); > if (current->il_next >= MAX_NUMNODES) -- 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