Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758474AbYHAM0Q (ORCPT ); Fri, 1 Aug 2008 08:26:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754550AbYHAM0D (ORCPT ); Fri, 1 Aug 2008 08:26:03 -0400 Received: from extu-mxob-1.symantec.com ([216.10.194.28]:40366 "EHLO extu-mxob-1.symantec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754287AbYHAM0B (ORCPT ); Fri, 1 Aug 2008 08:26:01 -0400 Date: Fri, 1 Aug 2008 13:25:57 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@blonde.site To: "Zhang, Yanmin" cc: Ingo Molnar , LKML Subject: Re: VolanoMark regression with 2.6.27-rc1 In-Reply-To: <1217474425.25608.150.camel@ymzhang> Message-ID: References: <1217474425.25608.150.camel@ymzhang> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1212 Lines: 29 On Thu, 31 Jul 2008, Zhang, Yanmin wrote: > > I tried to use git bisect to locate the root cause, but git bisect > always went back to 2.6.26. Then, I used my mechanical bisect script... .... > BTW, sysbench+mysql(oltp readonly) has about 15% regression, > but git bisect looks crazy again. I'm no git expert, but didn't see anyone else comment on this: you need to trust git more, it's like the Tour de France, occasionally venturing into other countries for a little while. Work which got merged into Linus's 2.6.26-git for 2.6.27-rc1 may well have been developed on a 2.6.26-rcN base in someone else's tree, and so the bisection may take you back there. I think this is getting commoner now, since Linus spoke out against rebasing: bisecting a net issue took me back to rc6-git and rc4-git, but did end up at the right commit. It can be nuisance if you don't notice at "make install" time, and reboot another kernel than the one you just built to test. Hugh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/