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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 82F09C432BE for ; Fri, 30 Jul 2021 20:49:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6CEFA60F00 for ; Fri, 30 Jul 2021 20:49:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231771AbhG3Utc (ORCPT ); Fri, 30 Jul 2021 16:49:32 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:58840 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230310AbhG3Ut3 (ORCPT ); Fri, 30 Jul 2021 16:49:29 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1627678163; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Uqi2XqGkI8u0LpsGdXDAcsLF+VndL2iSN5iYDs7Vj2E=; b=HS9dY7/0A/gGRrSJkeh/un5zvIV3mG7lRXVGzKipoXN6/ONKyo0q14r7kPGOxKRcfE4qzt UHkclIfsEDYfhnX9dKwF6+FB/EAyJfbJhmbii4akdtLMUDb2UXiS0wAgmRsCKpIrVVLyY8 Dx9ulhXvJvyAtCx40H4WBVjuKfGxTl/sdLmGkG24wlWRGaEmsQb3VoenytRP7sHtWS0CNw dmgAQiEIcHv6Tx119T64QiSdMVWzxQRoln89k36gQEyFGlbKRFXLBB+oo5g9x3GDSTsdlL ryU/19aaZO/IlPwAFRExYPPIggOPbgV4gYYj2o/H4nZDdcv2XNMxJXyDXOlYdg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1627678163; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Uqi2XqGkI8u0LpsGdXDAcsLF+VndL2iSN5iYDs7Vj2E=; b=ys5OwQ6pwA6iphMbA2d9rWNeASY9bCQNC9TYiTpQU3om337x2Bj9s67Cs6iebdU0qiaR4E Cg61xH8RY8+t3KBQ== To: Mike Galbraith , Sebastian Andrzej Siewior Cc: LKML , linux-rt-users@vger.kernel.org, Steven Rostedt , Peter Zijlstra Subject: Re: v5.14-rc3-rt1 losing wakeups? In-Reply-To: <2ae27233ab091d09a7d1e971a47144b40dd51fa0.camel@gmx.de> References: <20210730110753.jvli6alm63h5lefy@linutronix.de> <2ae27233ab091d09a7d1e971a47144b40dd51fa0.camel@gmx.de> Date: Fri, 30 Jul 2021 22:49:22 +0200 Message-ID: <87pmuzsf1p.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mike, On Fri, Jul 30 2021 at 17:21, Mike Galbraith wrote: > On Fri, 2021-07-30 at 13:07 +0200, Sebastian Andrzej Siewior wrote: >> Dear RT folks! >> >> I'm pleased to announce the v5.14-rc3-rt1 patch set. > > Damn, I was hoping to figure out wth is going on before the 62 patch > version of tglx/rtmutex branch made its way out into the big wide > world, but alas, I was too slow. > > I started meeting GUI hangs as soon as I merged the 62 patch series > into my 5.13-rt based master tree. I took tglx/rtmutex (977db8e523f5) > back to 5.13-rt to make sure it wasn't some booboo I had made in the > rolled forward tree, but the hangs followed the backport, and I just > met them in virgin v5.14-rc3-rt1, so unfortunately it wasn't some local > booboo, there's a bug lurking. Maybe a config sensitive one, as what > I'm seeing on my box seems unlikely to escape into the wild otherwise. > > First symptom is KDE/Plasma's task manager going comatose. Notice soon KDE/Plasma points at the new fangled rtmutex based ww_mutex from Peter. I tried to test the heck out of it... Which graphics driver is in use on that machine? > been helpful anyway, box at a glance looks fine. With lockdep enabled, > a failing kernel gets so buggered it isn't even able to crashdump. Ouch. Thanks, tglx