From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by kanga.kvack.org (Postfix) with ESMTP id B4CDC6B0253 for ; Mon, 17 Aug 2015 20:31:43 -0400 (EDT) Received: by pacgr6 with SMTP id gr6so119117051pac.2 for ; Mon, 17 Aug 2015 17:31:43 -0700 (PDT) Received: from mail-pa0-x232.google.com (mail-pa0-x232.google.com. [2607:f8b0:400e:c03::232]) by mx.google.com with ESMTPS id nw2si27054065pbb.40.2015.08.17.17.31.42 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 17 Aug 2015 17:31:43 -0700 (PDT) Received: by paccq16 with SMTP id cq16so75494731pac.1 for ; Mon, 17 Aug 2015 17:31:42 -0700 (PDT) Date: Mon, 17 Aug 2015 17:31:41 -0700 (PDT) From: David Rientjes Subject: Re: [Patch V3 2/9] kernel/profile.c: Replace cpu_to_mem() with cpu_to_node() In-Reply-To: <1439781546-7217-3-git-send-email-jiang.liu@linux.intel.com> Message-ID: References: <1439781546-7217-1-git-send-email-jiang.liu@linux.intel.com> <1439781546-7217-3-git-send-email-jiang.liu@linux.intel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Jiang Liu Cc: Andrew Morton , Mel Gorman , Mike Galbraith , Peter Zijlstra , "Rafael J . Wysocki" , Tang Chen , Tejun Heo , Tony Luck , linux-mm@kvack.org, linux-hotplug@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org On Mon, 17 Aug 2015, Jiang Liu wrote: > Function profile_cpu_callback() allocates memory without specifying > __GFP_THISNODE flag, so replace cpu_to_mem() with cpu_to_node() > because cpu_to_mem() may cause suboptimal memory allocation if > there's no free memory on the node returned by cpu_to_mem(). > Why is cpu_to_node() better with regard to free memory and NUMA locality? > It's safe to use cpu_to_mem() because build_all_zonelists() also > builds suitable fallback zonelist for memoryless node. > Why reference that cpu_to_mem() is safe if you're changing away from it? > Signed-off-by: Jiang Liu > --- > kernel/profile.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/profile.c b/kernel/profile.c > index a7bcd28d6e9f..d14805bdcc4c 100644 > --- a/kernel/profile.c > +++ b/kernel/profile.c > @@ -336,7 +336,7 @@ static int profile_cpu_callback(struct notifier_block *info, > switch (action) { > case CPU_UP_PREPARE: > case CPU_UP_PREPARE_FROZEN: > - node = cpu_to_mem(cpu); > + node = cpu_to_node(cpu); > per_cpu(cpu_profile_flip, cpu) = 0; > if (!per_cpu(cpu_profile_hits, cpu)[1]) { > page = alloc_pages_exact_node(node, -- 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