From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qc0-f175.google.com (mail-qc0-f175.google.com [209.85.216.175]) by kanga.kvack.org (Postfix) with ESMTP id 48C936B006E for ; Thu, 16 Apr 2015 12:01:38 -0400 (EDT) Received: by qcyk17 with SMTP id k17so8823169qcy.1 for ; Thu, 16 Apr 2015 09:01:38 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id 79si8686796qgo.20.2015.04.16.09.01.35 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 16 Apr 2015 09:01:36 -0700 (PDT) Message-ID: <552FDCD4.70108@redhat.com> Date: Thu, 16 Apr 2015 12:01:24 -0400 From: Rik van Riel MIME-Version: 1.0 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: owner-linux-mm@kvack.org List-ID: To: Mel Gorman , Linux-MM Cc: Hugh Dickins , Minchan Kim , Dave Hansen , Andi Kleen , LKML 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 -- 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