Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756137Ab2BGQ2W (ORCPT ); Tue, 7 Feb 2012 11:28:22 -0500 Received: from casper.infradead.org ([85.118.1.10]:39694 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754525Ab2BGQ2V (ORCPT ); Tue, 7 Feb 2012 11:28:21 -0500 Message-ID: <4F315113.5010804@kernel.dk> Date: Tue, 07 Feb 2012 17:28:03 +0100 From: Jens Axboe MIME-Version: 1.0 To: Tejun Heo CC: Linus Torvalds , Vivek Goyal , Shaohua Li , lkml , Knut Petersen , mroos@linux.ee Subject: Re: [PATCH] block: strip out locking optimization in put_io_context() References: <1328514611.21268.66.camel@sli10-conroe> <20120206151219.GC30752@redhat.com> <4F2FFB21.9000202@kernel.dk> <20120206163721.GF30752@redhat.com> <20120206164428.GA21292@google.com> <20120206172706.GB21292@google.com> <4F303506.9000201@kernel.dk> <20120206215451.GD21292@google.com> <4F30C96F.1000905@kernel.dk> <20120207162253.GG21292@google.com> In-Reply-To: <20120207162253.GG21292@google.com> X-Enigmail-Version: 1.3.5 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1370 Lines: 33 On 2012-02-07 17:22, Tejun Heo wrote: > Hello, Jens. > > On Tue, Feb 07, 2012 at 07:49:19AM +0100, Jens Axboe wrote: >>> I couldn't find any statiscally meaningful advantage of the >>> optimization with tight fork/exit tests w/ forced ioc creation on >>> fork, which gotta be the most pathological test case for the code >>> path. So, let's remove the ugly optimization. If I missed sth, we >>> can resurrect the simpler optimization later. Jens, this is on top of >>> linus#master without Shaohua's patch. >> >> OK, then I'm fine with cleaning it up. Applied, thanks Tejun. > > Hmmm... how about merging Shaohua's smaller fix first until we figure > out what's going on with the performance regression he's seeing? That was already merged in my tree. I don't see how it makes much difference in tracking the regression. You said that removing it made no difference for the find test case, so I'd be more comfortable getting rid of the nasty optimization. I'll send it when I have pending tomorrow, so there's still a full day to change things. We can just shuffle patches before then, not a problem. -- Jens Axboe -- 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/