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 F143EC4321E for ; Mon, 28 Nov 2022 20:39:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231251AbiK1Uja (ORCPT ); Mon, 28 Nov 2022 15:39:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233789AbiK1Uj0 (ORCPT ); Mon, 28 Nov 2022 15:39:26 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1891FB5A; Mon, 28 Nov 2022 12:39:24 -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 80AF2B80FD4; Mon, 28 Nov 2022 20:39:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5820EC433D6; Mon, 28 Nov 2022 20:39:21 +0000 (UTC) Date: Mon, 28 Nov 2022 15:39:19 -0500 From: Steven Rostedt To: Daniel Bristot de Oliveira Cc: Masami Hiramatsu , Jonathan Corbet , Juri Lelli , Clark Williams , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V3 2/3] tracing/osnoise: Add preempt/irq disable options Message-ID: <20221128153919.33c008d1@gandalf.local.home> In-Reply-To: <03d4a8522792fa3a51920c79f8a5074933a2fcb3.1669409262.git.bristot@kernel.org> References: <03d4a8522792fa3a51920c79f8a5074933a2fcb3.1669409262.git.bristot@kernel.org> 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-doc@vger.kernel.org On Fri, 25 Nov 2022 22:20:23 +0100 Daniel Bristot de Oliveira wrote: > @@ -1308,6 +1315,8 @@ static void notify_new_max_latency(u64 latency) > */ > static int run_osnoise(void) > { > + bool preempt_disable = test_bit(OSN_PREEMPT_DISABLE, &osnoise_options); > + bool irq_disable = test_bit(OSN_IRQ_DISABLE, &osnoise_options); bool irq_disable = test_bit(OSN_IRQ_DISABLE, &osnoise_options); bool preempt_disable = IS_ENABLED(CONFIG_PREEMPT) && !irq_disable && test_bit(OSN_PREEMPT_DISABLE, &osnoise_options); > struct osnoise_variables *osn_var = this_cpu_osn_var(); > u64 start, sample, last_sample; > u64 last_int_count, int_count; > @@ -1335,6 +1344,14 @@ static int run_osnoise(void) > */ > threshold = tracing_thresh ? : 5000; > > + /* > + * IRQ disable also implies in preempt disable. > + */ > + if (irq_disable) > + local_irq_disable(); if (preempt_disable) > + preempt_disable(); > + > /* > * Make sure NMIs see sampling first > */ > @@ -1422,16 +1439,21 @@ static int run_osnoise(void) > * cond_resched() > */ > if (IS_ENABLED(CONFIG_PREEMPT_RCU)) { > - local_irq_disable(); > + if (!irq_disable) > + local_irq_disable(); > + > rcu_momentary_dyntick_idle(); > - local_irq_enable(); > + > + if (!irq_disable) > + local_irq_enable(); > } > > /* > * For the non-preemptive kernel config: let threads runs, if > - * they so wish. > + * they so wish, unless set not do to so. > */ > - cond_resched(); > + if (!irq_disable && !preempt_disable) > + cond_resched(); > > last_sample = sample; > last_int_count = int_count; > @@ -1450,6 +1472,14 @@ static int run_osnoise(void) > */ > barrier(); > > + /* > + * Return to the preemptive state. > + */ if (preempt_disable) > + preempt_enable(); > + > + if (irq_disable) > + local_irq_enable(); -- Steve > /* > * Save noise info. > */