From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755305Ab3HPWbE (ORCPT ); Fri, 16 Aug 2013 18:31:04 -0400 Received: from relay2.sgi.com ([192.48.179.30]:48699 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754109Ab3HPWbC (ORCPT ); Fri, 16 Aug 2013 18:31:02 -0400 Date: Fri, 16 Aug 2013 14:31:55 -0500 From: Russ Anderson To: Yinghai Lu Cc: Andrew Morton , Tejun Heo , Linux MM , Linux Kernel Mailing List Subject: Re: [PATCH] memblock, numa: Binary search node id Message-ID: <20130816193154.GE22182@sgi.com> Reply-To: Russ Anderson References: <1376545589-32129-1-git-send-email-yinghai@kernel.org> <20130815134348.bb119a7987af0bb64ed77b7b@linux-foundation.org> <20130816190106.GD22182@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 16, 2013 at 12:15:21PM -0700, Yinghai Lu wrote: > On Fri, Aug 16, 2013 at 12:01 PM, Russ Anderson wrote: > > On Thu, Aug 15, 2013 at 01:43:48PM -0700, Andrew Morton wrote: > >> On Wed, 14 Aug 2013 22:46:29 -0700 Yinghai Lu wrote: > >> > >> > Current early_pfn_to_nid() on arch that support memblock go > >> > over memblock.memory one by one, so will take too many try > >> > near the end. > >> > > >> > We can use existing memblock_search to find the node id for > >> > given pfn, that could save some time on bigger system that > >> > have many entries memblock.memory array. > >> > >> Looks nice. I wonder how much difference it makes. > > > > Here are the timing differences for several machines. > > In each case with the patch less time was spent in __early_pfn_to_nid(). > > > > > > 3.11-rc5 with patch difference (%) > > -------- ---------- -------------- > > UV1: 256 nodes 9TB: 411.66 402.47 -9.19 (2.23%) > > UV2: 255 nodes 16TB: 1141.02 1138.12 -2.90 (0.25%) > > UV2: 64 nodes 2TB: 128.15 126.53 -1.62 (1.26%) > > UV2: 32 nodes 2TB: 121.87 121.07 -0.80 (0.66%) > > Time in seconds. > > > > Thanks. > > 9T one have more entries in memblock.memory? Yes. It is older hardware with smaller DIMMs and more of them. -- Russ Anderson, OS RAS/Partitioning Project Lead SGI - Silicon Graphics Inc rja@sgi.com