Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753305AbaGKHiY (ORCPT ); Fri, 11 Jul 2014 03:38:24 -0400 Received: from mga09.intel.com ([134.134.136.24]:37389 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751508AbaGKHiV (ORCPT ); Fri, 11 Jul 2014 03:38:21 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,642,1400050800"; d="scan'208";a="571590244" From: Jiang Liu To: Andrew Morton , Mel Gorman , David Rientjes , Mike Galbraith , Peter Zijlstra , "Rafael J . Wysocki" , Rik van Riel , Johannes Weiner , "Srivatsa S. Bhat" , Dave Hansen Cc: Jiang Liu , Tony Luck , linux-mm@kvack.org, linux-hotplug@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC Patch V1 28/30] mm: Update _mem_id_[] for every possible CPU when memory configuration changes Date: Fri, 11 Jul 2014 15:37:45 +0800 Message-Id: <1405064267-11678-29-git-send-email-jiang.liu@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1405064267-11678-1-git-send-email-jiang.liu@linux.intel.com> References: <1405064267-11678-1-git-send-email-jiang.liu@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Current kernel only updates _mem_id_[cpu] for onlined CPUs when memory configuration changes. So kernel may allocate memory from remote node for a CPU if the CPU is still in absent or offline state even if the node associated with the CPU has already been onlined. This patch tries to improve performance by updating _mem_id_[cpu] for each possible CPU when memory configuration changes, thus kernel could always allocate from local node once the node is onlined. We check node_online(cpu_to_node(cpu)) because: 1) local_memory_node(nid) needs to access NODE_DATA(nid) 2) try_offline_node(nid) just zeroes out NODE_DATA(nid) instead of free it Signed-off-by: Jiang Liu --- mm/page_alloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0ea758b898fd..de86e941ed57 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3844,13 +3844,13 @@ static int __build_all_zonelists(void *data) /* * We now know the "local memory node" for each node-- * i.e., the node of the first zone in the generic zonelist. - * Set up numa_mem percpu variable for on-line cpus. During - * boot, only the boot cpu should be on-line; we'll init the - * secondary cpus' numa_mem as they come on-line. During - * node/memory hotplug, we'll fixup all on-line cpus. + * Set up numa_mem percpu variable for all possible cpus + * if associated node has been onlined. */ - if (cpu_online(cpu)) + if (node_online(cpu_to_node(cpu))) set_cpu_numa_mem(cpu, local_memory_node(cpu_to_node(cpu))); + else + set_cpu_numa_mem(cpu, NUMA_NO_NODE); #endif } -- 1.7.10.4 -- 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/