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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 05288C43381 for ; Wed, 20 Mar 2019 11:17:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C61CD2184E for ; Wed, 20 Mar 2019 11:17:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="dNWQr1O8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727839AbfCTLRl (ORCPT ); Wed, 20 Mar 2019 07:17:41 -0400 Received: from mail-yw1-f65.google.com ([209.85.161.65]:42286 "EHLO mail-yw1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726006AbfCTLRk (ORCPT ); Wed, 20 Mar 2019 07:17:40 -0400 Received: by mail-yw1-f65.google.com with SMTP id e76so1629699ywa.9 for ; Wed, 20 Mar 2019 04:17:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=oz48NFB895ZbMvfJtIoZKMy1Z8ko+w/dzzts1G3S+gM=; b=dNWQr1O8riBE5SBH64MNYCjH2OGIKH6dXnBq2JFagwHS/Tj4yDj2jXaqmgKI1WCRvl 2EYOWIaxUlCPvys9mJM4GZVCf9zOQeemTpKFpV03DOzbhWAn1+MacflB8MSQx/MM6+Vs GqRaxS5D9EujIuXr+hpJdpT1Z/PUbHZcEqQNrj8JYnozC05nZTKNZHu0bHIXGy0ZV3XR DPSiLwbsG3Ut2W/CW35XPMOKqWY1lNvMCVOB0918tFCJYEU4r1Xcy8sKYDFl1Oj2rhUi CBwZlxTdwQlpkCY4sr7yQ/WQCiYgaQBOLY2dz9Ooso1AouVgcTDBES0YvaJfreklllqp 7xyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=oz48NFB895ZbMvfJtIoZKMy1Z8ko+w/dzzts1G3S+gM=; b=Ppr1ERiISjnWgbkHljvhkDvaDFKCoTzlMTbMKmWCSqku1tW2YCp4jawGceZ1HFlns9 ZuvtbygESMdp7klqGZVqt2/b1Z2XfpYV9dfo32TZ63L9E9v+rtZgn+R5htoNBLJJOVzP coFbNZM/54G+V5aejrQCeMcLq9291CE/W4UlcTvLtQEp/ujuFoYfQsy/puzzqFnHEejq J3bB83ojn3DNA5hEplovM2USqhWlMyayETEms9qailIPNTLJR4vYZjK1PxhkfJdKszSV xnEXaMMGLPkq3nemf6v0a3+uO7VPpfjNR817dOEGKh9wIg/H8w5eRQe1BjR61bHaEzqV t8kQ== X-Gm-Message-State: APjAAAXCOdHVUVMZEpKrCGwMxDtmnsI0v1tcExw2fXf7JBKH9RhHWwns fXJph9aEtnIjaoz9yYxKWyJwvz+XvXN+9MKc/SZmwg== X-Google-Smtp-Source: APXvYqxapFYhzkxwBa5nGgz9L4vXQ0kOsITaSrIu88JY0FUrOrivd7S9onpb6xm+fBp/AdIOYrwjzwnoBIgiU4gRwsg= X-Received: by 2002:a25:128b:: with SMTP id 133mr6474313ybs.325.1553080659767; Wed, 20 Mar 2019 04:17:39 -0700 (PDT) MIME-Version: 1.0 References: <20181130145622.26334-1-anders.roxell@linaro.org> <20181130101815.75038642@gandalf.local.home> In-Reply-To: <20181130101815.75038642@gandalf.local.home> From: Anders Roxell Date: Wed, 20 Mar 2019 12:17:29 +0100 Message-ID: Subject: Re: [PATCH v2] kernel/trace: fix watchdog soft lockup To: Steven Rostedt Cc: Ingo Molnar , Andrew Morton , Dmitry Vyukov , Linux Kernel Mailing List , Arnd Bergmann Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 30 Nov 2018 at 16:18, Steven Rostedt wrote: > > On Fri, 30 Nov 2018 15:56:22 +0100 > Anders Roxell wrote: > > > When building a allmodconfig kernel for arm64 and boot that in qemu, > > CONFIG_FTRACE_STARTUP_TEST gets enabled and that takes time so the > > watchdog expires and prints out a message like this: > > 'watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:1]' > > Depending on what the what test gets called from init_trace_selftests() > > it stays minutes in the loop. > > Rework so that function cond_resched() gets called in the > > init_trace_selftests loop. > > > > This looks fine to me. Should it be marked for stable, and pushed into > this release cycle, or wait till the next merge window? Steve, I'm sorry for the late reply and no its not urgent. Maybe it can make it into v5.2 ? Cheers, Anders > > -- Steve > > > Co-developed-by: Arnd Bergmann > > Signed-off-by: Arnd Bergmann > > Signed-off-by: Anders Roxell > > --- > > kernel/trace/trace.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > > index 5706599ed534..109becbc81ca 100644 > > --- a/kernel/trace/trace.c > > +++ b/kernel/trace/trace.c > > @@ -1547,6 +1547,10 @@ static __init int init_trace_selftests(void) > > pr_info("Running postponed tracer tests:\n"); > > > > list_for_each_entry_safe(p, n, &postponed_selftests, list) { > > + /* This loop can take minutes when sanitizers are enabled, so > > + * lets make sure we allow RCU processing. > > + */ > > + cond_resched(); > > ret = run_tracer_selftest(p->type); > > /* If the test fails, then warn and remove from available_tracers */ > > if (ret < 0) { >