Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752632AbbHQDQo (ORCPT ); Sun, 16 Aug 2015 23:16:44 -0400 Received: from mga01.intel.com ([192.55.52.88]:26329 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752484AbbHQDQk (ORCPT ); Sun, 16 Aug 2015 23:16:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,692,1432623600"; d="scan'208";a="543143549" From: Jiang Liu To: Andrew Morton , Mel Gorman , David Rientjes , Mike Galbraith , Peter Zijlstra , "Rafael J . Wysocki" , Tang Chen , Tejun Heo , Vlastimil Babka , Michal Hocko , Joonsoo Kim , Johannes Weiner , Alexander Duyck , Sasha Levin Cc: Jiang Liu , Tony Luck , linux-mm@kvack.org, linux-hotplug@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org Subject: [Patch V3 8/9] mm: Update _mem_id_[] for every possible CPU when memory configuration changes Date: Mon, 17 Aug 2015 11:19:05 +0800 Message-Id: <1439781546-7217-9-git-send-email-jiang.liu@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1439781546-7217-1-git-send-email-jiang.liu@linux.intel.com> References: <1439781546-7217-1-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 Content-Length: 1921 Lines: 48 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 beda41710802..bcfd66e66820 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4334,13 +4334,13 @@ 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/