Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758371AbaGQXKM (ORCPT ); Thu, 17 Jul 2014 19:10:12 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:50695 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757329AbaGQXKK (ORCPT ); Thu, 17 Jul 2014 19:10:10 -0400 Date: Thu, 17 Jul 2014 16:09:58 -0700 From: Nishanth Aravamudan To: benh@kernel.crashing.org Cc: Joonsoo Kim , David Rientjes , Wanpeng Li , Jiang Liu , Tony Luck , Fenghua Yu , linux-ia64@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [RFC 1/2] workqueue: use the nearest NUMA node, not the local one Message-ID: <20140717230958.GB32660@linux.vnet.ibm.com> References: <20140717230923.GA32660@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140717230923.GA32660@linux.vnet.ibm.com> X-Operating-System: Linux 3.13.0-30-generic (x86_64) User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14071723-1344-0000-0000-000002E7275A Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In the presence of memoryless nodes, the workqueue code incorrectly uses cpu_to_node() to determine what node to prefer memory allocations come from. cpu_to_mem() should be used instead, which will use the nearest NUMA node with memory. Signed-off-by: Nishanth Aravamudan diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 35974ac..0bba022 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -3547,7 +3547,12 @@ static struct worker_pool *get_unbound_pool(const struct workqueue_attrs *attrs) for_each_node(node) { if (cpumask_subset(pool->attrs->cpumask, wq_numa_possible_cpumask[node])) { - pool->node = node; + /* + * We could use local_memory_node(node) here, + * but it is expensive and the following caches + * the same value. + */ + pool->node = cpu_to_mem(cpumask_first(pool->attrs->cpumask)); break; } } @@ -4921,7 +4926,7 @@ static int __init init_workqueues(void) pool->cpu = cpu; cpumask_copy(pool->attrs->cpumask, cpumask_of(cpu)); pool->attrs->nice = std_nice[i++]; - pool->node = cpu_to_node(cpu); + pool->node = cpu_to_mem(cpu); /* alloc pool ID */ mutex_lock(&wq_pool_mutex); -- 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/