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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6C11C432C0 for ; Thu, 21 Nov 2019 01:59:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A45E2075A for ; Thu, 21 Nov 2019 01:59:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="BS4tfVw9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726165AbfKUB7b (ORCPT ); Wed, 20 Nov 2019 20:59:31 -0500 Received: from mail-pj1-f68.google.com ([209.85.216.68]:39702 "EHLO mail-pj1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725819AbfKUB7a (ORCPT ); Wed, 20 Nov 2019 20:59:30 -0500 Received: by mail-pj1-f68.google.com with SMTP id t103so704844pjb.6 for ; Wed, 20 Nov 2019 17:59:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=78FX/0eBvEiR/EpkRd0Cqr1DZXWBnvT4u3YgaZ7Oe6E=; b=BS4tfVw9kFQOU0gCyzrqOoDB36MzXmvaLWOsqdA1hvDkhExi8oz/7H0r6SNGz1e5l7 wtrqaYR2dHzd6/OCTrZCjMYnBRzoRq1JycKNzSyFo04QROnfIqAx9yJX8OM/t2XVZZ4O pHZZeUWTLiKiOH6gt8pjJUY44UPObPZDG/QHBgZkuEWo9qrpHnusMlwdJsuXymVbpFAJ 6VNIY+EeP7w4AqAkh/+eFDnlbGYQ7sPGQizh9kv455VB6MCDiqEC4xDG312GeRIJ3ipA IlBOQ0t2KgUR2qV2feFMHxdVIw6yYp4rr9lx6mLv9NDco2Wnduw1xeO44xOlMxYcm41q su7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=78FX/0eBvEiR/EpkRd0Cqr1DZXWBnvT4u3YgaZ7Oe6E=; b=NayIg2oOa6x8ab0OobKgnN3Co2BhBzeo3SRzv6axAwzvWylcZQORapdUExbh9Ts+6C e04485dSEgVwyqcyno5XPiPl3PD+v0Sp9qT4Z7HanAfcIjp42YtfnnV4mMqu7YFlWwsB pBNIiLFe89Zsv9YKquQM9jQKgJaL7xJ0lnOPxdfx1oJ9m6b/7cyi32fK8fg4Bs8bl14T v/Wd7VrxsIGUf6znXd2rzdHjlOXGZ7GGa6FXDeyTlWwIOvDKyi9pdq+1kov8+T9cFNhz 49eYC2GpJNo+fAMUgTGIlAL2PyGNqfRV2io63ED0/NHiKs+iUwvWaq5pYKXvDZ7lfQ2d JWHQ== X-Gm-Message-State: APjAAAXMtgdfq4vd/37LLLQXBrsjzS6i+RbqSnfCLcwl+wvyygSepSRk DlDe7h938j1tTMZl8OH2hcBdJQ== X-Google-Smtp-Source: APXvYqycAOiIHHP7Pql6Om3/mMUNgejRyqTx+PEO73XjED/jtnR31NppOw9Ye6HCWtba/40lYDrK9w== X-Received: by 2002:a17:902:b101:: with SMTP id q1mr6247437plr.154.1574301570208; Wed, 20 Nov 2019 17:59:30 -0800 (PST) Received: from [192.168.1.188] ([66.219.217.79]) by smtp.gmail.com with ESMTPSA id z2sm510274pgo.13.2019.11.20.17.59.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Nov 2019 17:59:29 -0800 (PST) Subject: Re: [PATCH] block,bfq: Skip tracing hooks if possible To: Dmitry Monakhov , linux-kernel@vger.kernel.org Cc: paolo.valente@linaro.org References: <20191101131110.18356-1-dmonakhov@gmail.com> From: Jens Axboe Message-ID: Date: Wed, 20 Nov 2019 16:11:03 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191101131110.18356-1-dmonakhov@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/1/19 7:11 AM, Dmitry Monakhov wrote: > In most cases blk_tracing is not active, but bfq_log_bfqq macro > generate pid_str unconditionally, which result in significant overhead. > > ## Test > modprobe null_blk > echo bfq > /sys/block/nullb0/queue/scheduler > fio --name=t --ioengine=libaio --direct=1 --filename=/dev/nullb0 \ > --runtime=30 --time_based=1 --rw=write --iodepth=128 --bs=4k > > # Results > | | baseline | w/ patch | gain | > | iops | 113.19K | 126.42K | +11% | Applied, thanks. -- Jens Axboe