From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qa0-f43.google.com (mail-qa0-f43.google.com [209.85.216.43]) by kanga.kvack.org (Postfix) with ESMTP id 8E5168299E for ; Tue, 6 May 2014 11:04:23 -0400 (EDT) Received: by mail-qa0-f43.google.com with SMTP id m5so5294999qaj.2 for ; Tue, 06 May 2014 08:04:23 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTP id 110si5271943qgv.113.2014.05.06.08.04.22 for ; Tue, 06 May 2014 08:04:22 -0700 (PDT) Message-ID: <5368F9F0.5070702@redhat.com> Date: Tue, 06 May 2014 11:04:16 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 01/17] mm: page_alloc: Do not update zlc unless the zlc is active References: <1398933888-4940-1-git-send-email-mgorman@suse.de> <1398933888-4940-2-git-send-email-mgorman@suse.de> In-Reply-To: <1398933888-4940-2-git-send-email-mgorman@suse.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman , Linux-MM , Linux-FSDevel Cc: Johannes Weiner , Vlastimil Babka , Jan Kara , Michal Hocko , Hugh Dickins , Linux Kernel On 05/01/2014 04:44 AM, Mel Gorman wrote: > The zlc is used on NUMA machines to quickly skip over zones that are full. > However it is always updated, even for the first zone scanned when the > zlc might not even be active. As it's a write to a bitmap that potentially > bounces cache line it's deceptively expensive and most machines will not > care. Only update the zlc if it was active. > > Signed-off-by: Mel Gorman Reviewed-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