From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48B59EB64DC for ; Mon, 26 Jun 2023 20:46:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229495AbjFZUqV (ORCPT ); Mon, 26 Jun 2023 16:46:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230310AbjFZUqS (ORCPT ); Mon, 26 Jun 2023 16:46:18 -0400 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2F79173C; Mon, 26 Jun 2023 13:46:16 -0700 (PDT) Received: by mail-pf1-x42d.google.com with SMTP id d2e1a72fcca58-6687446eaccso3488598b3a.3; Mon, 26 Jun 2023 13:46:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687812376; x=1690404376; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=abXWxshL/+u8xLEuocBOBOfPh4KOKawZQbGDTC33PZ4=; b=aEm69tH4y2vqT7mMQYdk2zYhVgNmyj+IlFnAcDUNbf7orO46rRaTy4wqhr+nUwASWw 26xA2AKIATgkRVCXu/0NJYm0zV1zmprviTuCSbU+zhyTxNG0ae97/26fVKVBX5RqGqpp WL6qn8jnnYV46NCKvPJUE6UmDHxsghh11ttLusz/5A/0cTY+oGg1+by30fWElEo/lnpb fMwtYp6+zeEBCuTBBWi1DZ0x6Y2akNNl3polboTYZhfTfmzO2kaIHwduCUUCVpV9SPWX yUH97BFulz1ASCV45RmPWS+6ddFCwNAK+vEF9ErRkcZhARs4fNOWWKnvDDn4eGOD/Uah U1jQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687812376; x=1690404376; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=abXWxshL/+u8xLEuocBOBOfPh4KOKawZQbGDTC33PZ4=; b=STb4BfK9UhD0TUQVlh5f0AGMR8tzk155+iT5uox1dDF6vy/Ty5WQGmC74chVCEc00k LI2W+fSp4KrD7nCggTK5j+AaGa2Sg9sSDfO8AXy42/lNMBm++5jJBeB0CkbOqY2HmrWw 2CWhC/q/CyqPjs3X5WmSj2j9IB939e/POOXUNcAg6+HuMut/vk2kar+WlXduB9ZcmHxk HztlJ6PQQPv4SqB0pguhdEt7HZB4n8MLwQt8utyrzj804To3uqGCIGOq/Imt4RU1KyXg w/xzPQIKDxuWgQ8i5DyxNbN35LeDWgyKOJDoGrjGakw0fd2PI8rngnGayvmBEA/PrGFL yjHA== X-Gm-Message-State: AC+VfDyKuu/e7TwS6FMTbhe1tp2Nweq4mk6f5Uccq7Co+XSaFphS34qC IEvbBDLPQnHgWbbHgMqMtd0= X-Google-Smtp-Source: ACHHUZ6kKDI19PV3gjIP1GxofqDbnPWWJC2aL4PzMWJSHKt/gwspnE1qLDSHSC/3/gnqL4T6MtuXDQ== X-Received: by 2002:a05:6a00:2e0e:b0:66b:6021:10fe with SMTP id fc14-20020a056a002e0e00b0066b602110femr12260119pfb.31.1687812375855; Mon, 26 Jun 2023 13:46:15 -0700 (PDT) Received: from localhost (dhcp-72-235-13-41.hawaiiantel.net. [72.235.13.41]) by smtp.gmail.com with ESMTPSA id p15-20020aa7860f000000b0064cca73d911sm4206288pfn.103.2023.06.26.13.46.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jun 2023 13:46:15 -0700 (PDT) Sender: Tejun Heo Date: Mon, 26 Jun 2023 10:46:15 -1000 From: Tejun Heo To: chengming.zhou@linux.dev Cc: axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, zhouchengming@bytedance.com Subject: Re: [PATCH v2 3/3] blk-mq: fix start_time_ns and alloc_time_ns for pre-allocated rq Message-ID: References: <20230626050405.781253-1-chengming.zhou@linux.dev> <20230626050405.781253-4-chengming.zhou@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230626050405.781253-4-chengming.zhou@linux.dev> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hello, I only glanced the blk-mq core part but in general this looks a lot better than the previous one. On Mon, Jun 26, 2023 at 01:04:05PM +0800, chengming.zhou@linux.dev wrote: > Note we don't skip setting alloc_time_ns and start_time_ns for all > pre-allocated rq, since the first returned rq still need to be set. This part is a bit curious for me tho. Why do we need to set it at batch allocation time and then at actual dispensing from the bat later? Who uses the alloc time stamp inbetween? Thanks. -- tejun