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 7D953C433EF for ; Mon, 27 Jun 2022 08:21:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233243AbiF0IVR (ORCPT ); Mon, 27 Jun 2022 04:21:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233178AbiF0IVP (ORCPT ); Mon, 27 Jun 2022 04:21:15 -0400 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1DA506279 for ; Mon, 27 Jun 2022 01:21:15 -0700 (PDT) Received: by mail-pl1-x62b.google.com with SMTP id l6so7486152plg.11 for ; Mon, 27 Jun 2022 01:21:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=QEdYkhc/vgHXgRfRmjc0nzpx3LEjhX5ml1rzqRnP/4s=; b=FBGP8QbnA/Q993e72LgTAcq4R2SHAg39ll9+8sV4mS/OaV53vVEBH3G9PmoL/WU5Ng EgGKJAzBw78GDCL2he0DRiOLKUjOFhu9QGvBP+wDybeVNL1aH0Uu3m8RA979bs8c6/JB GT19bNcR6pZDiEPk5dGI9EBAeVL2okq1qn6xzP5hsN8ZwKcWUvmi6zS2ytXG6s2QDXlu bUZ7692vrOpbQAIextdiUprzZ0S7YfY4JeIydOon1xbf6qnfWgOEBvkWi+z7rej7Qv3t 4CaUDdfON8gcc+Z0Pl+nCFP16aNZeaJbm+km/qFaJoNR/kYnDgKmrPMb2UKPxa1HxUID yn3w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=QEdYkhc/vgHXgRfRmjc0nzpx3LEjhX5ml1rzqRnP/4s=; b=HSq9ypvf89V96RjXb/6kyXXh01VbnTdeC1LKqcvYjGjtY8sw9Xf+wUvwK4KtO17r04 Eb0g/Ec9J+C3CD+/Xn48vmQENCnOo0tC/exo45wfn06omuJICqeQ/7xWXqJ63/QM3aCh 8/qJTAFKKS43jOQXfz/qJeGtpRyOirgx0rIMdDYX93aRkV/L+7vPHs/AHHCiaV8Bmlji jcKvSkRAAemwWrRiPWYufzPOXKes+SPEPxYEgBMRH/AGVwL/1gF5tPtVBnpAuyVTnqxv inJqJswJ0aRxxCekBeypvtOnMmQTJIsR61RtBa/DKJRHSOGjcpeq6CMAfqlLOuQb522/ RLlQ== X-Gm-Message-State: AJIora/npTr3T+HMDY0/rTWrfIkd1+4eNB98frXaxZ9M/QP0qLV4mNfR 8IzXw2mNr9S/pIsMHcAcsmU= X-Google-Smtp-Source: AGRyM1s4u5NPA/YOTVo+6n8fYNjPSjmjD7+mf9utAl655FKO6jiPaFvR5fTcoPhraldp8VpBWPz9EQ== X-Received: by 2002:a17:90a:ba04:b0:1ee:e6b0:edff with SMTP id s4-20020a17090aba0400b001eee6b0edffmr2201137pjr.153.1656318074516; Mon, 27 Jun 2022 01:21:14 -0700 (PDT) Received: from localhost ([121.167.227.144]) by smtp.gmail.com with ESMTPSA id u12-20020a17090341cc00b0016a6cd546d6sm6150889ple.251.2022.06.27.01.21.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jun 2022 01:21:14 -0700 (PDT) Sender: Tejun Heo Date: Mon, 27 Jun 2022 17:21:12 +0900 From: Tejun Heo To: Michal Hocko Cc: Petr Mladek , Lai Jiangshan , linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Andrew Morton , Linus Torvalds , Oleg Nesterov , "Eric W. Biederman" Subject: Re: re. Spurious wakeup on a newly created kthread Message-ID: References: <20220622140853.31383-1-pmladek@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Michal. On Mon, Jun 27, 2022 at 10:07:22AM +0200, Michal Hocko wrote: > So if somebody has woken up our thread from inside kthread() then it > doesn't have that pointer on the stack and I couldn't it find elsewhere > either. Maybe somebody has an idea where to look at. One way could be bpftrace'ing or printking __wake_up_common() and friends to dump backtrace if it's trying to wake a kthread whose comm starts with kworker/ and doesn't have (struct worker *)kthread_data(task)->pool set. Thanks. -- tejun