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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1638C433F5 for ; Fri, 30 Sep 2022 10:27:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232526AbiI3K1k (ORCPT ); Fri, 30 Sep 2022 06:27:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232465AbiI3KZE (ORCPT ); Fri, 30 Sep 2022 06:25:04 -0400 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F3AE1DA50 for ; Fri, 30 Sep 2022 03:19:49 -0700 (PDT) Received: from zn.tnic (p200300ea9733e70a329c23fffea6a903.dip0.t-ipconnect.de [IPv6:2003:ea:9733:e70a:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 28F5A1EC0666; Fri, 30 Sep 2022 12:19:39 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1664533179; 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: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=vjh05+Oz5jvzAv0RWE+u30Ynr1Qi+k7xCnkqZ2jc79Q=; b=P9OBFuoPmlTmSmvrgF7P3lz6+At9w+KEXr8JmOxZk9oOZxuoMD/99GP5EfKpQrbLIPPHg1 iQuDH+MloVpy/yfk9+lQd4Gvr+he3e4J6bMmVgBfZOdHgCJwBWhfPQ3AW+tb8UtzNM3csk 6NZ0G2UdTTgX6aLw9IHgyeQmkVxF0mY= Date: Fri, 30 Sep 2022 12:19:34 +0200 From: Borislav Petkov To: "Paul E. McKenney" , Peter Zijlstra Cc: x86-ml , lkml Subject: Re: INFO: task rcu_gp:3 blocked for more than 122 seconds. Message-ID: References: <20220929153722.GG4196@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220929153722.GG4196@paulmck-ThinkPad-P17-Gen-1> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 29, 2022 at 08:37:22AM -0700, Paul E. McKenney wrote: > As discussed on IRC, I got nuttin' on this one. Looks like an RCU > expedited grace period is stuck waiting for its workqueue kthread, and > that this workqueue kthread is stuck for some reason. Yeah, it is not that easy to repro - I need to wait a couple of minutes after it boots. Look at the timestamps: [ 249.149378] INFO: task rcu_gp:3 blocked for more than 122 seconds. ^^^^^^^^^^^^^^ But it looks like sched/core is the culprit because merging it into Linus master triggers it. Lemme bisect that. Stay tuned. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette