From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751973AbdI2J5v (ORCPT ); Fri, 29 Sep 2017 05:57:51 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:7471 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750926AbdI2J5t (ORCPT ); Fri, 29 Sep 2017 05:57:49 -0400 From: Zhen Lei To: Catalin Marinas , Will Deacon , linux-kernel , linux-api , Greg Kroah-Hartman , Michal Hocko , linux-mm CC: Tianhong Ding , Hanjun Guo , Libin , Kefeng Wang , Zhen Lei Subject: [PATCH v2 1/1] mm: only dispaly online cpus of the numa node Date: Fri, 29 Sep 2017 17:53:25 +0800 Message-ID: <1506678805-15392-2-git-send-email-thunder.leizhen@huawei.com> X-Mailer: git-send-email 1.9.5.msysgit.0 In-Reply-To: <1506678805-15392-1-git-send-email-thunder.leizhen@huawei.com> References: <1506678805-15392-1-git-send-email-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.177.23.164] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A010205.59CE184D.0041,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: e81be22d7ec363d8f77670df3133b8ff Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When I executed numactl -H(which read /sys/devices/system/node/nodeX/cpumap and display cpumask_of_node for each node), but I got different result on X86 and arm64. For each numa node, the former only displayed online CPUs, and the latter displayed all possible CPUs. Unfortunately, both Linux documentation and numactl manual have not described it clear. I sent a mail to ask for help, and Michal Hocko replied that he preferred to print online cpus because it doesn't really make much sense to bind anything on offline nodes. Signed-off-by: Zhen Lei Acked-by: Michal Hocko --- drivers/base/node.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/base/node.c b/drivers/base/node.c index 3855902..aae2402 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -27,13 +27,21 @@ static struct bus_type node_subsys = { static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf) { + ssize_t n; + cpumask_var_t mask; struct node *node_dev = to_node(dev); - const struct cpumask *mask = cpumask_of_node(node_dev->dev.id); /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */ BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1)); - return cpumap_print_to_pagebuf(list, buf, mask); + if (!alloc_cpumask_var(&mask, GFP_KERNEL)) + return 0; + + cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask); + n = cpumap_print_to_pagebuf(list, buf, mask); + free_cpumask_var(mask); + + return n; } static inline ssize_t node_read_cpumask(struct device *dev, -- 2.5.0