From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from 173-166-109-252-newengland.hfc.comcastbusiness.net ([173.166.109.252]:55595 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754481Ab2LRI3I (ORCPT ); Tue, 18 Dec 2012 03:29:08 -0500 Message-ID: <50D02951.4030608@kernel.dk> Date: Tue, 18 Dec 2012 09:29:05 +0100 From: Jens Axboe MIME-Version: 1.0 Subject: Re: Latency spikes with 'thread' option References: <80B89753B40C5141A3E2D53FE7A2A8A930030D7E@NTXBOIMBX02.micron.com> <50C9D5CA.9000904@kernel.dk> <80B89753B40C5141A3E2D53FE7A2A8A930031AC5@NTXBOIMBX02.micron.com> <50D01990.7080102@kernel.dk> In-Reply-To: <50D01990.7080102@kernel.dk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: fio-owner@vger.kernel.org List-Id: fio@vger.kernel.org To: "Sam Bradshaw (sbradshaw)" Cc: "fio@vger.kernel.org" , "Mike Berhan (mberhan)" On 2012-12-18 08:21, Jens Axboe wrote: > Good analysis and I believe you are correct. It's not safely shared and > should be thread local. A quick test here with the below seems to > indicate that that is indeed the issue, I don't see any time weirdness > with that applied. Bah, so that didn't work on all the supported platforms (notably OSX does not have support for __thread). I've committed a patch that should work across platforms, please give the current fio git a try (5d879392 or newer). -- Jens Axboe