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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 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 833CAC433DF for ; Thu, 23 Jul 2020 15:39:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66BF720737 for ; Thu, 23 Jul 2020 15:39:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729592AbgGWPja (ORCPT ); Thu, 23 Jul 2020 11:39:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:57192 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726761AbgGWPj3 (ORCPT ); Thu, 23 Jul 2020 11:39:29 -0400 Received: from oasis.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AA748206D8; Thu, 23 Jul 2020 15:39:28 +0000 (UTC) Date: Thu, 23 Jul 2020 11:39:27 -0400 From: Steven Rostedt To: John Ogness Cc: Vincent Whitchurch , jbaron@akamai.com, mingo@redhat.com, kernel@axis.com, corbet@lwn.net, linux-kernel@vger.kernel.org, Petr Mladek , Sergey Senozhatsky Subject: Re: [PATCH] dynamic debug: allow printing to trace event Message-ID: <20200723113927.581af808@oasis.local.home> In-Reply-To: <87blk6cosb.fsf@jogness.linutronix.de> References: <20200721141105.16034-1-vincent.whitchurch@axis.com> <20200721173045.540ae500@oasis.local.home> <87eep3zmg9.fsf@jogness.linutronix.de> <20200722112525.694880d3@oasis.local.home> <87blk6cosb.fsf@jogness.linutronix.de> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 23 Jul 2020 16:08:44 +0206 John Ogness wrote: > For me a trace event represents a specific point in the kernel code. But > this new printk trace event, instead, represents general log > redirection. I do not oppose it, but it feels like a hack to me. In > contrast, simply setting a dynamic printk flag to write the message > string to the trace buffer (without also activating some pseudo trace > event) feels more natural. I agree with your sentiment. But my experience with the kernel is, if you create an API for one subsystem, other subsystems are destined to (ab)use it. Now, trace_array_vprintk() is available too, which acts just like trace_printk(), but requires creating a separate trace buffer to write to. I'm fine with this because it wont cause noise in the top level buffer. > > Just sharing my thoughts, as requested. Appreciated ;-) -- Steve