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 BD2ABC433F5 for ; Mon, 20 Dec 2021 20:50:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229930AbhLTUuy (ORCPT ); Mon, 20 Dec 2021 15:50:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229888AbhLTUuy (ORCPT ); Mon, 20 Dec 2021 15:50:54 -0500 Received: from mail-io1-xd36.google.com (mail-io1-xd36.google.com [IPv6:2607:f8b0:4864:20::d36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 397CDC061574 for ; Mon, 20 Dec 2021 12:50:54 -0800 (PST) Received: by mail-io1-xd36.google.com with SMTP id x6so14825001iol.13 for ; Mon, 20 Dec 2021 12:50:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=from:to:cc:in-reply-to:references:subject:message-id:date :mime-version:content-transfer-encoding; bh=c9XJhvmZT/MX0Dmn9tb6Hib0N0oOR8X9axj2urQ+ZSE=; b=QhIEVb1sdRi9DSwei1pPOGnv4H5m/kGldy1JqqHn/TX5YJFyloAxEF0Q/vQ+XgoHaF f/notsBLa7mUrVpdhZuNF8FVhfR4oLy6gP8rjlGPWJD+inb7UgvHgcTMWtGUH+cbI4PG gyi0p1tLClbr6amGO+vUZMSHJLv48/UP7Ip60msMiDs3E9Io0Eqgx8JjJAyDHK5XAbb4 l85Vm04lswpBKT70EoYygMKyEvthclWkiBJ6szdQ2oTAvbcw6yLrGoirNiGp+8X4zmtE xgi3zQfI+MdxkKcooDKGbM8E24HHfqZG9IImZkDtnMIR4z7U5wG5ayD3jRGhiMDZDjuW cfMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:in-reply-to:references:subject :message-id:date:mime-version:content-transfer-encoding; bh=c9XJhvmZT/MX0Dmn9tb6Hib0N0oOR8X9axj2urQ+ZSE=; b=lMGY+zi3SPsYY6JB17q2gti1gPOd+VtOsuMcJya4zcqYi+Pl+Bse3apNZWFDJT8W39 o+Ghddw5bytH5+plzSPHD3axemshi+jqQMAOo/wU7lPBSiLL2+bBekAncZP8AkZBBb2j nDpe2hqSGflBrCeAf4rH5nRFgWmQvLryRvEKZXEU1ZflZpHnAOQgOZIGWJ2OATTGqLgQ Ns2JAwbML7HRiFML3o0+O2gmhw0/zWAzETbeZXLlCdjpj4FWTwO2XkBngvt2LqHLGtAr Y7fy0pi8jANRxwad/iV06nzMR5YeFZt1okx+zqKcNkxtYp+Eo59JJ2TOcfTQNKRDzicL 1BLA== X-Gm-Message-State: AOAM533V25ROagCiSrAZ93d8XDCODtD8Ftt17A0p9tfoFRxNpebelQvp 5z3irb4l7jEk4YN7CxMvU9L9qQ== X-Google-Smtp-Source: ABdhPJzG7HYpgxUCbycJzyxcFvYpTM27QXhTJAT+2v6Ij02m6D8f14QUwUR71k55FnP+H0wQFCoL7A== X-Received: by 2002:a05:6602:1552:: with SMTP id h18mr9327079iow.183.1640033453635; Mon, 20 Dec 2021 12:50:53 -0800 (PST) Received: from x1.localdomain ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id t9sm1349672ilu.50.2021.12.20.12.50.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Dec 2021 12:50:53 -0800 (PST) From: Jens Axboe To: Steven Rostedt , Ingo Molnar , linux-kernel@vger.kernel.org, Wander Lairson Costa , "open list:BLOCK LAYER" Cc: Thomas Gleixner , Sebastian Andrzej Siewior In-Reply-To: <20211220192827.38297-1-wander@redhat.com> References: <20211220192827.38297-1-wander@redhat.com> Subject: Re: [PATCH v5 1/1] blktrace: switch trace spinlock to a raw spinlock Message-Id: <164003345302.532019.10882095301451527257.b4-ty@kernel.dk> Date: Mon, 20 Dec 2021 13:50:53 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, 20 Dec 2021 16:28:27 -0300, Wander Lairson Costa wrote: > The running_trace_lock protects running_trace_list and is acquired > within the tracepoint which implies disabled preemption. The spinlock_t > typed lock can not be acquired with disabled preemption on PREEMPT_RT > because it becomes a sleeping lock. > The runtime of the tracepoint depends on the number of entries in > running_trace_list and has no limit. The blk-tracer is considered debug > code and higher latencies here are okay. > > [...] Applied, thanks! [1/1] blktrace: switch trace spinlock to a raw spinlock commit: 361c81dbc58c8aa230e1f2d556045fa7bc3eb4a3 Best regards, -- Jens Axboe