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 606E6C4167B for ; Fri, 9 Dec 2022 20:36:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229865AbiLIUgC (ORCPT ); Fri, 9 Dec 2022 15:36:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229738AbiLIUf7 (ORCPT ); Fri, 9 Dec 2022 15:35:59 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD3DBA0F8C; Fri, 9 Dec 2022 12:35:57 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 77C2BB82910; Fri, 9 Dec 2022 20:35:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43800C433EF; Fri, 9 Dec 2022 20:35:54 +0000 (UTC) Date: Fri, 9 Dec 2022 15:35:52 -0500 From: Steven Rostedt To: Daniel Bristot de Oliveira Cc: Masami Hiramatsu , Jonathan Corbet , Juri Lelli , Clark Williams , Bagas Sanjaya , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V4 2/3] tracing/osnoise: Add preempt and/or irq disabled options Message-ID: <20221209153552.4c7099cd@gandalf.local.home> In-Reply-To: References: X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 30 Nov 2022 19:19:10 +0100 Daniel Bristot de Oliveira wrote: Hi Daniel, As I was adding this series, I noticed an issue that needs to be fixed. > static int run_osnoise(void) > { > + bool irq_disable = test_bit(OSN_IRQ_DISABLE, &osnoise_options); > struct osnoise_variables *osn_var = this_cpu_osn_var(); > u64 start, sample, last_sample; > u64 last_int_count, int_count; > @@ -1315,11 +1323,18 @@ static int run_osnoise(void) > s64 total, last_total = 0; > struct osnoise_sample s; > unsigned int threshold; > + bool preempt_disable; Let's use a different name for the above variable. > u64 runtime, stop_in; > u64 sum_noise = 0; > int hw_count = 0; > int ret = -1; > > + /* > + * Disabling preemption is only required if IRQs are enabled, > + * and the options is set on. > + */ > + preempt_disable = !irq_disable && test_bit(OSN_PREEMPT_DISABLE, &osnoise_options); > + > /* > * Considers the current thread as the workload. > */ > @@ -1335,6 +1350,15 @@ static int run_osnoise(void) > */ > threshold = tracing_thresh ? : 5000; > > + /* > + * Apply PREEMPT and IRQ disabled options. > + */ > + if (irq_disable) > + local_irq_disable(); > + > + if (preempt_disable) > + preempt_disable(); > + The only reason the above works is because preempt_disable() is a macro. If it was a function, then it would likely fail to build (as you are overriding the name with a bool variable). -- Steve