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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 482D2C46470 for ; Wed, 8 Aug 2018 00:48:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF634216F7 for ; Wed, 8 Aug 2018 00:48:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF634216F7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726927AbeHHDFY (ORCPT ); Tue, 7 Aug 2018 23:05:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:55038 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726503AbeHHDFX (ORCPT ); Tue, 7 Aug 2018 23:05:23 -0400 Received: from vmware.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (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 3D950216F5; Wed, 8 Aug 2018 00:48:22 +0000 (UTC) Date: Tue, 7 Aug 2018 20:48:20 -0400 From: Steven Rostedt To: Joel Fernandes Cc: Joel Fernandes , LKML , "Cc: Android Kernel" , Boqun Feng , Byungchul Park , Ingo Molnar , Masami Hiramatsu , Mathieu Desnoyers , Namhyung Kim , Paul McKenney , Peter Zijlstra , Thomas Glexiner , Tom Zanussi Subject: Re: [PATCH v12 3/3] tracing: Centralize preemptirq tracepoints and unify their usage Message-ID: <20180807204820.50b83c6d@vmware.local.home> In-Reply-To: <6D0A3FD6-2190-4CC0-A3C0-7B3759E73243@google.com> References: <20180730222423.196630-1-joel@joelfernandes.org> <20180730222423.196630-4-joel@joelfernandes.org> <20180806155058.5ee875f4@gandalf.local.home> <20180806214300.13e63523@gandalf.local.home> <20180807094954.5137972d@gandalf.local.home> <446AE5F2-39E0-46B6-8E0B-207E003DBF20@google.com> <20180807103410.4fe203cb@gandalf.local.home> <20180807110906.3a1b0ac4@gandalf.local.home> <6B9E5DC9-0859-41B4-9B72-A7D85E9EA2AD@google.com> <20180807194515.4e549c1a@gandalf.local.home> <6D0A3FD6-2190-4CC0-A3C0-7B3759E73243@google.com> X-Mailer: Claws Mail 3.15.1 (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 Tue, 07 Aug 2018 19:54:13 -0400 Joel Fernandes wrote: > >OK, I hit this bug, but it's not because of the partial revert. This > >bug seems it needs to be another partial revert. I like you movement of > >the code, but I'm starting to doubt that we can use a trace event as a > >hook for critical areas yet. Well, not until we can use srcu in NMI. > > > > I sent a patch to use srcu for all tracepoints including nmi. That > patch also removes this warning and fixes the one other issue masami > reported (hot plug causing a warning). Is it one I can take, or does Paul have it? I'll need it to continue with this as is, because I can't pass my tests without triggering that warning (and that fails the test). > > If Paul and Mathieu can confirm SRCU works on offline CPUs that would > be great. Yes please. > > It's just this one warning or anything else that makes you feel > tracepoints for critical paths isn't feasible? Currently I'm down to this, but I can't get past my first test in my ktest suite, because it fails here. -- Steve