From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 55CD93D646B for ; Wed, 25 Feb 2026 16:59:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772038798; cv=none; b=PCzX6OcZ3p87mTi2D6WGg1GFrogIQ8VV6AA6FxhO/qeSszUspXegC2lWSBZs3Hku0C3ZP3R4NNJGuxnu5xnV2E3K1NkmZlYRMqNgQJPIN4m5DOrol7s/HyWRMzPrjZvfK5U046PSgbBDe3Pi9Jmfli709kYOZIjvE48gVruuvrE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772038798; c=relaxed/simple; bh=E+PFY3KJ41sWn2EAoDPd8bwCo4o7mOgES37Xa7Rl0JE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eHMgBAC9KsiObdGEP77HZaH+/50qHHVz4GwZpBPiRymMedZWUNOPNVmR3s9nEp0WrLI/UenkFibvd9LH0+fb7HBGokbhpV/itnikgLW8D7mryNHQ1LZxRyHS8D8/j0dDgMo79Ledpu8OFbsrEpleGx4uSxMu9qdEXmtUB/3t7p0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=KKmjekFl; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Ep0cYBTj; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="KKmjekFl"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Ep0cYBTj" Date: Wed, 25 Feb 2026 17:59:54 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1772038795; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KxkawXcqlJEdwsRv02qGmm0KC1QlDfGnzfXeShzLCiM=; b=KKmjekFlURlIb0tLBLm/mV4m2cXvqSukb0DRhea0RCqoCPiY9d8/YTTi10/oCjaMU3YstJ MwOubMIFliFtUhiyBqj1F4ZMprKEXYwQhMSkavJoQHPCjF+WSx7OJQPKJU3nuIU1Mo7j0X ipUswu+ShFN2023HC6KgIZeM4Y1nlLlgY8CoJTA4mQDLVFjEsao0/muP3xaNzZJacScwTj IUF6F69sYhl6naQ56jvl/+3JNmmCz7dnbzBstlLu2cmkksVYyScurfj6DVysA0LRn1umuj ZsSKUutLY2OJ+vGxOAmv/5SVvCHwUgdKDvdja9LcIleEVJNb0CizL9DQu+lqMg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1772038795; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KxkawXcqlJEdwsRv02qGmm0KC1QlDfGnzfXeShzLCiM=; b=Ep0cYBTjLIy2X+dYnYcP7OSME0abOwsobgQ3OH6o2//37bo44g6NXDAL47nVvX/8sy15wE sP5YT8B2R25J7QDg== From: Sebastian Andrzej Siewior To: Bert Karwatzki Cc: Tejun Heo , Thomas Gleixner , calvin@wbinvd.org, dschatzberg@meta.com, peterz@infradead.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, Steven Rostedt Subject: Re: ~90s reboot delay with v6.19 and PREEMPT_RT Message-ID: <20260225165954.180aRkaV@linutronix.de> References: <20260219164648.3014-1-spasswolf@web.de> <20260225154341.32AjXoVi@linutronix.de> <6abee0b4bca811680a7f7fb6ab70bf27c6805cf5.camel@web.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: <6abee0b4bca811680a7f7fb6ab70bf27c6805cf5.camel@web.de> On 2026-02-25 17:37:56 [+0100], Bert Karwatzki wrote: > I've done two testruns with this debug patch (The persistant log buffer w= orks now, thanks > again to Steven Rostedt): =E2=80=A6 > This if from PREEMPT_RT log, there*s a long pause in which cgroup_task_de= ad() is not called Yeah, I don't know why. The irq-work is invoked slightly delayed so that part is working. | irq_work-24 0..... 1501734us : cgrp_dead_tasks_iwork_fn: Kill ffff= 888101588000 (sd-close)-1964 | systemd--1 1..... 1502194us : sched_process_wait: comm=3Dsystemd = pid=3D1963 prio=3D120 | systemd--1 1..... 1502547us : sched_process_wait: comm=3Dsystemd = pid=3D0 prio=3D120 | systemd--1 1..... 1502771us : sched_process_wait: comm=3Dsystemd = pid=3D1964 prio=3D120 | systemd--1 1..... 1502819us : sched_process_wait: comm=3Dsystemd = pid=3D0 prio=3D120 | systemd--1 1..... 1502835us : sched_process_wait: comm=3Dsystemd = pid=3D0 prio=3D120 | rcuc/1-31 1b...1 1524116us : sched_process_free: comm=3D(sd-clos= e) pid=3D1964 prio=3D120 the gap | systemd--1 3..... 90610397us : sched_process_wait: comm=3Dsystemd= pid=3D0 prio=3D120 | systemd--1 3..... 90611469us : sched_process_wait: comm=3Dsystemd= pid=3D1829 prio=3D120 So for some reason systemd stops killing tasks. It complains about still running gpg-agent and ssh-agent but both are long gone. Sebastian