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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 18AA5C4332B for ; Mon, 23 Mar 2020 09:28:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E01F12072D for ; Mon, 23 Mar 2020 09:28:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MQL04WvN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727709AbgCWJ2B (ORCPT ); Mon, 23 Mar 2020 05:28:01 -0400 Received: from us-smtp-delivery-74.mimecast.com ([63.128.21.74]:27736 "EHLO us-smtp-delivery-74.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727669AbgCWJ2B (ORCPT ); Mon, 23 Mar 2020 05:28:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584955679; 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=0eue0jrc67xfJnfJk9ICQ1xtxeUcbBK4TygDF+Ayn20=; b=MQL04WvNeM5m2QtCPGIjpFrJnnXPrTjxR3MWksat7OlNdS9nZ2UP3AOgGvC7FQWEzGXdrq yrxuey3KhJGuH4JJuU0rxMs6EXhdAGfn0o8hkO7z/DfB/2KQiNEgLlPZwRRm4VWhPGBQkv lVIFcts870zovjhRhBIls1KAtIINPu4= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-392-PrClEjvfNwu1Wo8dCd4OeA-1; Mon, 23 Mar 2020 05:27:58 -0400 X-MC-Unique: PrClEjvfNwu1Wo8dCd4OeA-1 Received: by mail-wm1-f72.google.com with SMTP id v184so3309198wme.7 for ; Mon, 23 Mar 2020 02:27:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=0eue0jrc67xfJnfJk9ICQ1xtxeUcbBK4TygDF+Ayn20=; b=eW84g2UmHa9BSv1flQKm09HGv7olgqVdOGyFx9O2GKQ6C9WaE4d4OktMj99bgXKmuN 9QDvJrXa8bBgwuq2Yvxy5tYiuYUYXaTjL8CPd7KIG5H29DSjhhdDsl+G1JjtGxkYeJQO uAVJpmGrRU+9/RI9jrhm1tn4bxsJsrla8Lv1L+R7ZBJ6EFq5/2Lk8PQ38FQEveoBuEyG 4Mojj54M+RKdbbK+12F3Xtwa3+k/91gBo92sEnTtK+J6MH3hPfXJAayzE7q4JcA4fc44 Cg1gKckI5EPnxpTeHC+gGFoeKPCH1pVYfL3KAVuxezi7v4t7NN9il7f0ZQliaMpBZEA1 OdOQ== X-Gm-Message-State: ANhLgQ2MdsShcuNSOIvs0ALM+OQvSm0ehFM2KQzAuZ7hNeexD/axISSR a6xowa4i+hhQRNcuByldX6K3d3OC/N4YLlZQTMai7T0mVkN8PWWOUYS8yBHxtFdKIUlruG6+nFT 3ZqplKYF/0isLj4uf9ZJRa9ry X-Received: by 2002:a1c:9658:: with SMTP id y85mr26269461wmd.63.1584955676994; Mon, 23 Mar 2020 02:27:56 -0700 (PDT) X-Google-Smtp-Source: ADFU+vun9jWmUPgL/rJK95Cry9OUaAEuL0bLGvpk0q05iiMD9MI+PPsMSsLdAGIhBJfiJtQ7oLokCw== X-Received: by 2002:a1c:9658:: with SMTP id y85mr26269434wmd.63.1584955676758; Mon, 23 Mar 2020 02:27:56 -0700 (PDT) Received: from localhost.localdomain ([151.29.194.179]) by smtp.gmail.com with ESMTPSA id e1sm23474045wrx.90.2020.03.23.02.27.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Mar 2020 02:27:56 -0700 (PDT) Date: Mon, 23 Mar 2020 10:27:54 +0100 From: Juri Lelli To: Lucas Stach Cc: Steven Rostedt , linux-kernel@vger.kernel.org, Ingo Molnar , Peter Zijlstra , Vincent Guittot , Dietmar Eggemann , Ben Segall , Mel Gorman Subject: Re: help needed in debugging missed wakeup(?) Message-ID: <20200323092754.GD14300@localhost.localdomain> References: <20200320140618.048714c9@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 20/03/20 20:04, Lucas Stach wrote: [...] > My hope was that someone would could guide me a little with an educated > guess, to make those trace_printks more helpful. The lockup is hard to > trigger and there's other unrelated system activity going on, even when > the relevant user task is stuck, so randomly sprinkling debug > statements will generate lots of output to filter down. I'd start by enabling sched:sched_pi_setprio (or adding trace_printks around there to confirm your suspicion). Once that is confirmed, I'd try to look at update_curr_dl::throttle and verify if the misbehaving task was indeed throttled at some point; it shouldn't be, because dl_boosted flag should be set for it at this point (maybe check this condition as well). Best, Juri