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 6D5A8C28CF6 for ; Wed, 1 Aug 2018 20:03:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ECC9A208A4 for ; Wed, 1 Aug 2018 20:03:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECC9A208A4 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 S1729764AbeHAVus (ORCPT ); Wed, 1 Aug 2018 17:50:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:33226 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725938AbeHAVus (ORCPT ); Wed, 1 Aug 2018 17:50:48 -0400 Received: from gandalf.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 CB514208A3; Wed, 1 Aug 2018 20:03:21 +0000 (UTC) Date: Wed, 1 Aug 2018 16:03:20 -0400 From: Steven Rostedt To: Thomas Gleixner Cc: Erica Bugden , linux-kernel@vger.kernel.org, peterz@infradead.org, anna-maria@linutronix.de, bigeasy@linutronix.de Subject: Re: [PATCH] ftrace: Add missing check for existing hwlat thread Message-ID: <20180801160320.3a4c63f7@gandalf.local.home> In-Reply-To: References: <1533120354-22923-1-git-send-email-erica.bugden@linutronix.de> <20180801154006.580806cc@gandalf.local.home> X-Mailer: Claws Mail 3.16.0 (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 Wed, 1 Aug 2018 21:59:38 +0200 (CEST) Thomas Gleixner wrote: > > This looks like it is treating the symptom and not the disease. > > My bad. We looked at the other instances of tracers and they all have > protection against this kind of call sequence ... Probably because they were all fixing the symptom ;-) I'm going to keep Erica's patch and add a WARN_ON() to it just in case. But can you still check if the patch I gave fixes it too? -- Steve