From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755774Ab0I1Qf2 (ORCPT ); Tue, 28 Sep 2010 12:35:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:26230 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755107Ab0I1Qf1 (ORCPT ); Tue, 28 Sep 2010 12:35:27 -0400 Message-ID: <4CA21906.1080002@redhat.com> Date: Tue, 28 Sep 2010 18:34:14 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc13 Lightning/1.0b3pre Thunderbird/3.1.4 MIME-Version: 1.0 To: Robin Holt CC: Nathan Fontenot , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@ozlabs.org, Greg KH , Dave Hansen , KAMEZAWA Hiroyuki Subject: Re: [PATCH 0/8] v2 De-Couple sysfs memory directories from memory sections References: <4CA0EBEB.1030204@austin.ibm.com> <4CA1E338.6070201@redhat.com> <20100928151218.GJ14068@sgi.com> In-Reply-To: <20100928151218.GJ14068@sgi.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/28/2010 05:12 PM, Robin Holt wrote: > > Why not update sysfs directory creation to be fast, for example by > > using an rbtree instead of a linked list. This fixes an > > implementation problem in the kernel instead of working around it > > and creating a new ABI. > > Because the old ABI creates 129,000+ entries inside > /sys/devices/system/memory with their associated links from > /sys/devices/system/node/node*/ back to those directory entries. > > Thankfully things like rpm, hald, and other miscellaneous commands scan > that information. On our 8 TB test machine, hald runs continuously > following boot for nearly an hour mostly scanning useless information > from /sys/ I see - so the problem wasn't just kernel internal; the ABI itself was unsuitable. Too bad this wasn't considered at the time it was added. (129k entries / 1 hour = 35 entries/sec; not very impressive) -- error compiling committee.c: too many arguments to function