From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f177.google.com (mail-pd0-f177.google.com [209.85.192.177]) by kanga.kvack.org (Postfix) with ESMTP id 6A3016B0035 for ; Fri, 1 Nov 2013 17:23:53 -0400 (EDT) Received: by mail-pd0-f177.google.com with SMTP id p10so4363904pdj.22 for ; Fri, 01 Nov 2013 14:23:53 -0700 (PDT) Received: from psmtp.com ([74.125.245.111]) by mx.google.com with SMTP id gj2si5771169pac.109.2013.11.01.14.23.51 for ; Fri, 01 Nov 2013 14:23:52 -0700 (PDT) Message-ID: <52741BE0.4070306@redhat.com> Date: Fri, 01 Nov 2013 17:23:44 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH] mm: cache largest vma References: <1383337039.2653.18.camel@buesod1.americas.hpqcorp.net> In-Reply-To: <1383337039.2653.18.camel@buesod1.americas.hpqcorp.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Davidlohr Bueso Cc: Andrew Morton , Hugh Dickins , Michel Lespinasse , Ingo Molnar , Mel Gorman , Guan Xuetao , aswin@hp.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org On 11/01/2013 04:17 PM, Davidlohr Bueso wrote: > While caching the last used vma already does a nice job avoiding > having to iterate the rbtree in find_vma, we can improve. After > studying the hit rate on a load of workloads and environments, > it was seen that it was around 45-50% - constant for a standard > desktop system (gnome3 + evolution + firefox + a few xterms), > and multiple java related workloads (including Hadoop/terasort), > and aim7, which indicates it's better than the 35% value documented > in the code. > > By also caching the largest vma, that is, the one that contains > most addresses, there is a steady 10-15% hit rate gain, putting > it above the 60% region. This improvement comes at a very low I suspect this will especially help when also using automatic numa balancing, which causes periodic page faults. Acked-by: Rik van Riel -- All rights reversed -- 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