Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752917AbZCIHIo (ORCPT ); Mon, 9 Mar 2009 03:08:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751945AbZCIHId (ORCPT ); Mon, 9 Mar 2009 03:08:33 -0400 Received: from smtp-out.google.com ([216.239.45.13]:62348 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751933AbZCIHIc convert rfc822-to-8bit (ORCPT ); Mon, 9 Mar 2009 03:08:32 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:content-transfer-encoding:x-system-of-record; b=RnkP0VgBu61msvyhIjjxzOKIfBbn7MRzZtJKfM9CsDPwTuWGzv4erRYLC1ihTXAKe NeZDSgDM0+wtpAWxVSrqw== MIME-Version: 1.0 In-Reply-To: References: <6599ad830903080953na692dcfh7f455bfe46a895c3@mail.gmail.com> Date: Mon, 9 Mar 2009 00:08:26 -0700 Message-ID: <6599ad830903090008u4418e7efie137c87c6ac42e55@mail.gmail.com> Subject: Re: [patch -mm] cpusets: add memory_slab_hardwall flag From: Paul Menage To: David Rientjes Cc: Andrew Morton , Christoph Lameter , Pekka Enberg , Matt Mackall , Randy Dunlap , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1923 Lines: 55 Another thought - it would probably be better to call this flag kernel_mem_hardwall or mem_hardwall_kernel, to avoid hard-coding its name to be slab-specific. Paul On Sun, Mar 8, 2009 at 2:38 PM, David Rientjes wrote: > On Sun, 8 Mar 2009, Paul Menage wrote: > >> > +/** >> > + * current_cpuset_object_allowed - can a slab object be allocated on a node? >> > + * @node: the node for object allocation >> > + * @flags: allocation flags >> > + * >> > + * Return non-zero if object is allowed, zero otherwise. >> > + */ >> > +int current_cpuset_object_allowed(int node, gfp_t flags) >> > +{ >> > + ? ? ? return !is_slab_hardwall(task_cs(current)) || >> > + ? ? ? ? ? ? ?cpuset_node_allowed_hardwall(node, flags); >> > +} >> > + >> >> This should be in rcu_read_lock()/rcu_read_unlock() in order to safely >> dereference the result of task_cs(current) >> > > I've folded the following into the patch, thanks Paul. > --- > ?kernel/cpuset.c | ? ?8 ++++++-- > ?1 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/kernel/cpuset.c b/kernel/cpuset.c > --- a/kernel/cpuset.c > +++ b/kernel/cpuset.c > @@ -1205,8 +1205,12 @@ int current_cpuset_is_being_rebound(void) > ?*/ > ?int current_cpuset_object_allowed(int node, gfp_t flags) > ?{ > - ? ? ? return !is_slab_hardwall(task_cs(current)) || > - ? ? ? ? ? ? ?cpuset_node_allowed_hardwall(node, flags); > + ? ? ? int is_hardwall; > + > + ? ? ? rcu_read_lock(); > + ? ? ? is_hardwall = is_slab_hardwall(task_cs(current)); > + ? ? ? rcu_read_unlock(); > + ? ? ? return !is_hardwall || cpuset_node_allowed_hardwall(node, flags); > ?} > > ?static int update_relax_domain_level(struct cpuset *cs, s64 val) -- 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/