From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Chen Subject: Re: [RFC, PATCH] Avoid hot statistics cache line in ext4 extent cache Date: Fri, 13 Apr 2012 10:53:32 -0700 Message-ID: <1334339612.3796.2.camel@schen9-DESK> References: <20120323221715.GA6712@tassilo.jf.intel.com> <20120324031357.GA5690@tassilo.jf.intel.com> <4F70F51F.8030405@linux.intel.com> <20120326235707.GC19489@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Andi Kleen , Ted Ts'o , Vivek Haldar , Andreas Dilger , linux-ext4@vger.kernel.org To: Linus Torvalds Return-path: Received: from mga09.intel.com ([134.134.136.24]:41135 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751555Ab2DMRxc (ORCPT ); Fri, 13 Apr 2012 13:53:32 -0400 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, 2012-04-13 at 10:42 -0700, Linus Torvalds wrote: > On Wed, Apr 11, 2012 at 9:59 AM, Andi Kleen wrote: > > > > Ping. This scalability problem is still in 3.4-rc* and causes > > major slowdowns. > > Do you have numbers? > In a benchmark that does mmaped-read, there is a 28% speed up after getting rid of the counters. > > Can we please revert fix it or revert > > 556b27abf73833923d5cd4be80006292e1b31662 before release. > > That commit ID doesn't make any sense, and doesn't seem to have > anything to do with any statistics counters that your email talks > about. So regardless, you'd need to explain why that commit causes the > problems you talk about, I'm not going to revert a random commit that > doesn't even look what you describe. > > Ted? > > Linus