From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f169.google.com (mail-ie0-f169.google.com [209.85.223.169]) by kanga.kvack.org (Postfix) with ESMTP id A28BA6B0071 for ; Mon, 21 Jul 2014 13:33:48 -0400 (EDT) Received: by mail-ie0-f169.google.com with SMTP id tp5so7120435ieb.14 for ; Mon, 21 Jul 2014 10:33:48 -0700 (PDT) Received: from e39.co.us.ibm.com (e39.co.us.ibm.com. [32.97.110.160]) by mx.google.com with ESMTPS id d9si30854812igo.13.2014.07.21.10.33.47 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 21 Jul 2014 10:33:48 -0700 (PDT) Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 21 Jul 2014 11:33:46 -0600 Received: from b03cxnp08026.gho.boulder.ibm.com (b03cxnp08026.gho.boulder.ibm.com [9.17.130.18]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id 2B98619D8052 for ; Mon, 21 Jul 2014 11:33:35 -0600 (MDT) Received: from d03av06.boulder.ibm.com (d03av06.boulder.ibm.com [9.17.195.245]) by b03cxnp08026.gho.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s6LHWVsJ5505304 for ; Mon, 21 Jul 2014 19:32:31 +0200 Received: from d03av06.boulder.ibm.com (loopback [127.0.0.1]) by d03av06.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id s6LHbpDx010352 for ; Mon, 21 Jul 2014 11:37:53 -0600 Date: Mon, 21 Jul 2014 10:33:42 -0700 From: "Paul E. McKenney" Subject: Re: [RFC Patch V1 01/30] mm, kernel: Use cpu_to_mem()/numa_mem_id() to support memoryless node Message-ID: <20140721173342.GB8690@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1405064267-11678-1-git-send-email-jiang.liu@linux.intel.com> <1405064267-11678-2-git-send-email-jiang.liu@linux.intel.com> <20140711151405.GK16041@linux.vnet.ibm.com> <20140721171527.GA4156@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140721171527.GA4156@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Nishanth Aravamudan Cc: Jiang Liu , Andrew Morton , Mel Gorman , David Rientjes , Mike Galbraith , Peter Zijlstra , "Rafael J . Wysocki" , Dipankar Sarma , Balbir Singh , Thomas Gleixner , Jens Axboe , Frederic Weisbecker , Jan Kara , Ingo Molnar , Christoph Hellwig , "Srivatsa S. Bhat" , Roman Gushchin , Xie XiuQi , Tony Luck , linux-mm@kvack.org, linux-hotplug@vger.kernel.org, linux-kernel@vger.kernel.org On Mon, Jul 21, 2014 at 10:15:27AM -0700, Nishanth Aravamudan wrote: > Hi Paul, > > On 11.07.2014 [08:14:05 -0700], Paul E. McKenney wrote: > > On Fri, Jul 11, 2014 at 03:37:18PM +0800, Jiang Liu wrote: > > > When CONFIG_HAVE_MEMORYLESS_NODES is enabled, cpu_to_node()/numa_node_id() > > > may return a node without memory, and later cause system failure/panic > > > when calling kmalloc_node() and friends with returned node id. > > > So use cpu_to_mem()/numa_mem_id() instead to get the nearest node with > > > memory for the/current cpu. > > > > > > If CONFIG_HAVE_MEMORYLESS_NODES is disabled, cpu_to_mem()/numa_mem_id() > > > is the same as cpu_to_node()/numa_node_id(). > > > > > > Signed-off-by: Jiang Liu > > > > For the rcutorture piece: > > > > Acked-by: Paul E. McKenney > > > > Or if you separate the kernel/rcu/rcutorture.c portion into a separate > > patch, I will queue it separately. > > Just FYI, based upon a separate discussion with Tejun and others, it > seems to be preferred to avoid the proliferation of cpu_to_mem > throughout the kernel blindly. For kthread_create_on_node(), I'm going > to try and fix the underlying issue and so you, as the caller, should > still specify the NUMA node you are running the kthread on > (cpu_to_node), not where you expect the memory to come from > (cpu_to_mem). Even better!!! ;-) Thanx, Paul -- 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