From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 625326B0003 for ; Thu, 22 Feb 2018 20:36:21 -0500 (EST) Received: by mail-pf0-f199.google.com with SMTP id q11so3378618pff.19 for ; Thu, 22 Feb 2018 17:36:21 -0800 (PST) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTPS id b5si772419pgv.317.2018.02.22.17.36.19 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 22 Feb 2018 17:36:19 -0800 (PST) Date: Fri, 23 Feb 2018 09:37:14 +0800 From: Aaron Lu Subject: Re: [PATCH v2 1/2] free_pcppages_bulk: do not hold lock when picking pages to free Message-ID: <20180223013714.GA4338@intel.com> References: <20180124023050.20097-1-aaron.lu@intel.com> <20180124163926.c7ptagn655aeiut3@techsingularity.net> <20180125072144.GA27678@intel.com> <20180215120608.g5wj2qb2thkkzu5e@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180215120608.g5wj2qb2thkkzu5e@techsingularity.net> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Huang Ying , Dave Hansen , Kemi Wang , Tim Chen , Andi Kleen , Michal Hocko , Vlastimil Babka On Thu, Feb 15, 2018 at 12:06:08PM +0000, Mel Gorman wrote: > On Thu, Jan 25, 2018 at 03:21:44PM +0800, Aaron Lu wrote: > > When freeing a batch of pages from Per-CPU-Pages(PCP) back to buddy, > > the zone->lock is held and then pages are chosen from PCP's migratetype > > list. While there is actually no need to do this 'choose part' under > > lock since it's PCP pages, the only CPU that can touch them is us and > > irq is also disabled. > > > > Moving this part outside could reduce lock held time and improve > > performance. Test with will-it-scale/page_fault1 full load: > > > > kernel Broadwell(2S) Skylake(2S) Broadwell(4S) Skylake(4S) > > v4.15-rc4 9037332 8000124 13642741 15728686 > > this patch 9608786 +6.3% 8368915 +4.6% 14042169 +2.9% 17433559 +10.8% > > > > What the test does is: starts $nr_cpu processes and each will repeatedly > > do the following for 5 minutes: > > 1 mmap 128M anonymouse space; > > 2 write access to that space; > > 3 munmap. > > The score is the aggregated iteration. > > > > https://github.com/antonblanchard/will-it-scale/blob/master/tests/page_fault1.c > > > > Acked-by: Mel Gorman > > Signed-off-by: Aaron Lu > > It looks like this series may have gotten lost because it was embedded > within an existing thread or else it was the proximity to the merge > window. I suggest a rebase, retest and resubmit unless there was some > major objection that I missed. Patch 1 is fine by me at least. I never > explicitly acked patch 2 but I've no major objection to it, just am a tad > uncomfortable with prefetch magic sauce in general. Thanks for the suggestion. I just got back from vacation and will send out once I collected all the required date. -- 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