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 A6AA6C433EF for ; Mon, 20 Dec 2021 23:46:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230447AbhLTXqB (ORCPT ); Mon, 20 Dec 2021 18:46:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230219AbhLTXqA (ORCPT ); Mon, 20 Dec 2021 18:46:00 -0500 Received: from mail-io1-xd31.google.com (mail-io1-xd31.google.com [IPv6:2607:f8b0:4864:20::d31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 622DCC061574 for ; Mon, 20 Dec 2021 15:46:00 -0800 (PST) Received: by mail-io1-xd31.google.com with SMTP id y16so15456532ioc.8 for ; Mon, 20 Dec 2021 15:46:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=qhtVAR+sknJEbgT3KYqmYZUz0TiJ2iQjq2f6Rqlsa2k=; b=XxElCAKWWJs2pQKrBlJFbACA67N2Vl59wigT46QPpfxbIZYqq9XJ72QJuKq+2ZE3sG ZBAP0t7vZCvdkJtpyQZgsx2MyzMh58D0uzF6+CSNsqiNPCkXG+m1c5znt9SeHTW0WLkt 2GA6dIXavpJopJMLWH+j/CizTQk9SDZDewCBzjvQykY043C7blJ1GSk69iEyftKTR+9K 0u9k6jcaIZL0lL2bewC/cElBXgvayAuggxmDUrnIHNSNtQ0DvdoGzhEuqTEymxoFqGbQ lz0xOBH3J/PJzGffW0JZljufm7Y4dOuvDkIbL8wP47u0czxrs5X7EEPtRmz27vRETAZu ezQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=qhtVAR+sknJEbgT3KYqmYZUz0TiJ2iQjq2f6Rqlsa2k=; b=t3rpvRCsgPduAg2J2TFdOO5xGBuSF5cZlxrAD55DjMq4Ka/UWJn6XeiDkdY2ya6ecg OEjLt/zN6NZ99vgtfe8U+R6XStAs/+DU+0kqnaELNbG1rt//6ynl2HCEWTzdPd99fffA CKAhsoLje1IW7BW7OF8ZgxiOpRkGUNWimY/Jl/JCirr8axOtWzt8iHcXoIAsU0qA8zas ZIKM5etwtsLaFwZ78Y8KSZpdlbKsuUgB8nOnydIs6uLjulEAMJH8n/QfaAgu/Lee0AIN TDaNdTKtV0dx8nScYEkNfqqU3KFu9cReXK/nI1TCRzySUymqrUL5ahISX5slQ8qpplPD vO4w== X-Gm-Message-State: AOAM531GYT546259juvTTI+iv+FfUfIUMMGx48OUyXWY+PrfsNgjyYVN hAu2Z5OnzuQBV1q+L4LeLQw/yg== X-Google-Smtp-Source: ABdhPJzFnCR55CYq0guosnTFrAh3y1n2+5JK2rxvkxO9p/h+QGR5kXv2EVonphXgb6l69YDxEzRaMg== X-Received: by 2002:a05:6602:2c50:: with SMTP id x16mr305051iov.114.1640043959752; Mon, 20 Dec 2021 15:45:59 -0800 (PST) Received: from [192.168.1.116] ([66.219.217.159]) by smtp.gmail.com with ESMTPSA id l1sm9509232ioj.29.2021.12.20.15.45.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 20 Dec 2021 15:45:59 -0800 (PST) Subject: Re: [PATCH v5 1/1] blktrace: switch trace spinlock to a raw spinlock To: Steven Rostedt Cc: Wander Costa , Wander Lairson Costa , open list , Ingo Molnar , "open list:BLOCK LAYER" , Thomas Gleixner , Sebastian Andrzej Siewior References: <20211220192827.38297-1-wander@redhat.com> <8340efc7-f922-fb8c-772c-de72cefe3470@kernel.dk> <2f2f5003-e1bf-15ce-32cd-a543634ba880@kernel.dk> <76333783-cb3a-d1b7-5e40-d07014c4e2c0@kernel.dk> <20211220183046.7193720d@rorschach.local.home> From: Jens Axboe Message-ID: <4d110c2a-2e70-8fc1-a16e-cd576c646a39@kernel.dk> Date: Mon, 20 Dec 2021 16:45:57 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20211220183046.7193720d@rorschach.local.home> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 12/20/21 4:30 PM, Steven Rostedt wrote: > On Mon, 20 Dec 2021 13:49:47 -0700 > Jens Axboe wrote: > >> Alright, fair enough, mistakes happen. I think the patch looks fine, my >> main dislike is that it's Yet Another things that needs special RT >> handling. But I guess that's how it is... > > It's not really "yet another thing". That's because in general tracing > needs special RT handling (and a lot of other special handling, not > just RT). blktrace falls under the tracing category, and this just > falls under one more thing to make tracing work with RT. This isn't the first patch like this I've applied. I'm not saying this is an issue with tracing, just that it's another one of these "spinlocks are now preemptible/sleeping with RT" and that necessitates changes like this. -- Jens Axboe