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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 428F7C4332D for ; Fri, 20 Mar 2020 03:09:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 25C0320754 for ; Fri, 20 Mar 2020 03:09:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726975AbgCTDJu (ORCPT ); Thu, 19 Mar 2020 23:09:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:36386 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726614AbgCTDJt (ORCPT ); Thu, 19 Mar 2020 23:09:49 -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 DD12B2070A; Fri, 20 Mar 2020 03:09:46 +0000 (UTC) Date: Thu, 19 Mar 2020 23:09:45 -0400 From: Steven Rostedt To: "Paul E. McKenney" Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Ben Segall , Mel Gorman Subject: Re: [PATCH RFC v2 tip/core/rcu 01/22] sched/core: Add function to sample state of locked-down task Message-ID: <20200319230945.3f4701ed@oasis.local.home> In-Reply-To: <20200320024943.GA29649@paulmck-ThinkPad-P72> References: <20200319001024.GA28798@paulmck-ThinkPad-P72> <20200319001100.24917-1-paulmck@kernel.org> <20200319132238.75a034c3@gandalf.local.home> <20200319173525.GI3199@paulmck-ThinkPad-P72> <20200320024943.GA29649@paulmck-ThinkPad-P72> 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, 19 Mar 2020 19:49:43 -0700 "Paul E. McKenney" wrote: > > The current setup is very convenient for the use cases thus far. It > > allows the function to say "Yeah, I was called, but I couldn't do > > anything", thus allowing the caller to make exactly one check to know > > that corrective action is required. > > And here is another use case that led me to take this approach. > The trc_inspect_reader_notrunning() function in the patch below is passed > to try_invoke_on_locked_down_task() whose caller can continue testing > just the return value from try_invoke_on_locked_down_task() to work out > what to do next. > > Thoughts? Other use cases? Note, I made this comment before looking at the use cases in the later patches. I was looking at it for a more generic purpose, but I'm not sure there is one. It's fine as is for now. -- Steve