From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030330Ab2CGUGb (ORCPT ); Wed, 7 Mar 2012 15:06:31 -0500 Received: from mail-iy0-f174.google.com ([209.85.210.174]:53451 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030212Ab2CGUGa (ORCPT ); Wed, 7 Mar 2012 15:06:30 -0500 Date: Wed, 7 Mar 2012 12:06:26 -0800 From: Greg KH To: Xiachen Dong Cc: linux-kernel@vger.kernel.org Subject: Re: 2.6.36 and higher version kernel slower than 2.6.25.1 kernel? Message-ID: <20120307200626.GA3086@kroah.com> References: <20120307194728.GA26341@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 07, 2012 at 02:59:35PM -0500, Xiachen Dong wrote: > > Thanks for your reply. > > There could be quite some code change from 2.6.25.1 to 2.6.36. What we > are doing now is to find the first version starting from 2.6.25.1 that > has the performance hit. Then we start comparing the code and see > what's changed. Looks like 2.6.28.7 is OK. 'git bisect' will do all of this for you pretty quickly, I'd recommend doing that (but start by saying that 2.6.28 is good, that will speed it up.) > Haven't tried 3.2.29 yet because 3.2.29 probably won't be available in > the BSP from our board manufacturer in the near future. I'll try > 3.2.29 tonight on X86 CPU anyway and get you updated. Why isn't the BSP upstream? Any pointers to where the patch for it is, to get that merged properly? thanks, greg k-h