From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f197.google.com (mail-wr0-f197.google.com [209.85.128.197]) by kanga.kvack.org (Postfix) with ESMTP id ADE1A6B03E7 for ; Wed, 21 Jun 2017 08:25:07 -0400 (EDT) Received: by mail-wr0-f197.google.com with SMTP id x23so30042368wrb.6 for ; Wed, 21 Jun 2017 05:25:07 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id p89si12696963wma.78.2017.06.21.05.25.06 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 21 Jun 2017 05:25:06 -0700 (PDT) Subject: Re: [PATCH] mm: avoid taking zone lock in pagetypeinfo_showmixed References: <1498045643-12257-1-git-send-email-vinmenon@codeaurora.org> From: Vlastimil Babka Message-ID: Date: Wed, 21 Jun 2017 14:24:22 +0200 MIME-Version: 1.0 In-Reply-To: <1498045643-12257-1-git-send-email-vinmenon@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Vinayak Menon , akpm@linux-foundation.org, iamjoonsoo.kim@lge.com, zhongjiang@huawei.com, sergey.senozhatsky@gmail.com, sudipm.mukherjee@gmail.com, hannes@cmpxchg.org, mgorman@techsingularity.net, mhocko@suse.com, bigeasy@linutronix.de, rientjes@google.com, minchan@kernel.org Cc: linux-mm@kvack.org On 06/21/2017 01:47 PM, Vinayak Menon wrote: > pagetypeinfo_showmixedcount_print is found to take a lot of > time to complete and it does this holding the zone lock and > disabling interrupts. In some cases it is found to take more > than a second (On a 2.4GHz,8Gb RAM,arm64 cpu). Avoid taking > the zone lock similar to what is done by read_page_owner, > which means possibility of inaccurate results. > > Signed-off-by: Vinayak Menon Acked-by: Vlastimil Babka walk_zones_in_node() becomes quite ugly though, multiple bool params are not nice, and both are there for single special cases. Wonder if replacing this with a new for_each_zone_node() helper would make this better. OTOH it's now isolated only to vmstat.c. -- 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