From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753397AbbDPQBr (ORCPT ); Thu, 16 Apr 2015 12:01:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33340 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752212AbbDPQBj (ORCPT ); Thu, 16 Apr 2015 12:01:39 -0400 Message-ID: <552FDCD4.70108@redhat.com> Date: Thu, 16 Apr 2015 12:01:24 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Mel Gorman , Linux-MM CC: Hugh Dickins , Minchan Kim , Dave Hansen , Andi Kleen , LKML Subject: Re: [PATCH 4/4] mm: migrate: Batch TLB flushing when unmapping pages for migration References: <1429179766-26711-1-git-send-email-mgorman@suse.de> <1429179766-26711-5-git-send-email-mgorman@suse.de> In-Reply-To: <1429179766-26711-5-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/16/2015 06:22 AM, Mel Gorman wrote: > Page reclaim batches multiple TLB flushes into one IPI and this patch teaches > page migration to also batch any necessary flushes. MMtests has a THP scale > microbenchmark that deliberately fragments memory and then allocates THPs > to stress compaction. It's not a page reclaim benchmark and recent kernels > avoid excessive compaction but this patch reduced system CPU usage > > 4.0.0 4.0.0 > baseline batchmigrate-v1 > User 970.70 1012.24 > System 2067.48 1840.00 > Elapsed 1520.63 1529.66 > > Note that this particular workload was not TLB flush intensive with peaks > in interrupts during the compaction phase. The 4.0 kernel peaked at 345K > interrupts/second, the kernel that batches reclaim TLB entries peaked at > 13K interrupts/second and this patch peaked at 10K interrupts/second. > > Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel