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=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 40AFCC433E0 for ; Fri, 5 Jun 2020 13:20:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 212EB206E6 for ; Fri, 5 Jun 2020 13:20:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="vfuK+UVD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726916AbgFENUM (ORCPT ); Fri, 5 Jun 2020 09:20:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726711AbgFENUM (ORCPT ); Fri, 5 Jun 2020 09:20:12 -0400 Received: from mail-ej1-x641.google.com (mail-ej1-x641.google.com [IPv6:2a00:1450:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA49AC08C5C2; Fri, 5 Jun 2020 06:20:11 -0700 (PDT) Received: by mail-ej1-x641.google.com with SMTP id n24so10099793ejd.0; Fri, 05 Jun 2020 06:20:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=v47Il7vhv7sHVs8oOXJuoJtKJwqprhyn7oIEIBkCU74=; b=vfuK+UVDgp02YsTy1Z0t1Haq+q1Hb9iQe8Kho+Ga7o+s+tlF+Zpt8165HykwEhhM/H 8koxSxNTJPHYCxMVGVteX3p2pFGq3wLkmtU1HobyOiB4kbaFEISyilYEVAVNLyo8Vrts HVgwcHK8JY42pX21Cw3KdozE7Ql/096/eoncMWbMC3/z+SaTYOGHQdvfdC1SnH7v1lz6 2R6tUn52hQd4lNpOWyhouSKei9j/cn0SFG2+qRmmpW0iYsznOMap+r6hwaBuI1E3AI2N sO1J019qtXoK+I5JqJe9XFPMWHrptUw9CM5kokoB+rmPnpeX2z9hfoPIcSA6+Ylvg3Jn IadA== 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=v47Il7vhv7sHVs8oOXJuoJtKJwqprhyn7oIEIBkCU74=; b=B7LslWIoPqOjeJcyclo/uRhN0M+stQvTN2i2iXoyrCbh3knAarlblr39wmJTRQumVD v9OoLVQ641Ru5NESt1+veGq/pEJSx+tPNJT+3GL9w3RFCn9rTW0nIFP0LHQMgIKmLNbY +t47yH7KV8vKtwC2Il+pl3IIco+NE7ILhmSWOgDWw0nRvm8sV+ZXKFaG5HBUABvyioEg aiO008RfxUBGLxSw4E66ANzfsL5eShsAXiQOWskZ/iQKQIIG39Upby6kuFq3TbSvKnrl 62ssccsIWVs7rdnyIagiefdUKkTgB4XGTWmCk07u8Si5wmgGhYuRLHSTC75EFcqk/lzc nOgQ== X-Gm-Message-State: AOAM531K3OVcc4/q8G6+TTppXBznaaHAfQwCuTn6ERqgUj1VNP3BK5Lc 1A+UJZUxMEsNKCGa8SLchPWFtjz8aqPvniBbsPcNNg== X-Google-Smtp-Source: ABdhPJx0a4RRvx48K6OMYFjpT5V8FKLA/03O6HWnvHyKo+y+5Pqtm4EjQEUvmL9i5Cmk94QgBTiaF5VZkYlW/Hv1PDs= X-Received: by 2002:a17:906:af84:: with SMTP id mj4mr8339543ejb.473.1591363210450; Fri, 05 Jun 2020 06:20:10 -0700 (PDT) MIME-Version: 1.0 References: <4781d250-9a29-cef3-268d-7d83c98bf16a@gmail.com> <87wo4lekm5.fsf@kurt> In-Reply-To: <87wo4lekm5.fsf@kurt> From: Vladimir Oltean Date: Fri, 5 Jun 2020 16:19:59 +0300 Message-ID: Subject: Re: stress-ng --hrtimers hangs system To: Kurt Kanzenbach Cc: linux-rt-users@vger.kernel.org, lkml , rcu@vger.kernel.org, Colin King Content-Type: text/plain; charset="UTF-8" Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org Hi Kurt, On Fri, 5 Jun 2020 at 15:57, Kurt Kanzenbach wrote: > > Hi Vladimir, > > On Fri Jun 05 2020, Vladimir Oltean wrote: > > Hi, > > > > I was testing stress-ng on an ARM64 box and I found that it can be killed instantaneously with a --hrtimers 1 test: > > https://github.com/ColinIanKing/stress-ng/blob/master/stress-hrtimers.c > > The console shell locks up immediately after starting the process, and I get this rcu_preempt splat after 21 seconds, > > letting me know that the grace-periods kernel thread could not run: > > interesting. Just tested this on an ARM64 box with v5.6-rt and the > stress-ng hrtimer test works fine. No lockups, cyclictest results are > looking good. So maybe this is v5.7 related. > > Thanks, > Kurt This is not actually v5.7 related. I could also reproduce it on a downstream 5.4 kernel which is how I originally saw it. Thanks, -Vladimir