From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 A9B801B87FD for ; Fri, 13 Dec 2024 11:10:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734088210; cv=none; b=VuVHcBz+mw+PjZBBx+vbb+iDPDeFoBlJIDGC7dFJGW1Aju5dA/7F8/thMfzPFHwhWgHFa9ukcdu/cNVURZPr6Fagv6u0AWh0YenHeLAQ8PCZ61dbpGzbhH1E9F+o1rygSl2LdthwQTRJooqpG2uupgSAgrSpI6Wrn+2QHXxCG9I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734088210; c=relaxed/simple; bh=QVINjB2G8IvulEdr2DtHkqMFNSr0D/cyFc6vAqV0yHo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ObNDLVz9jfA+MjiS3Kn7OngLVForkdpSrz6kdXJXi16kdu9LEV1BZsQh3F5+1H0mewkeqXcneGTR7jzimedZSq263wmgnbparhu5etKdfY6H6JvtXcyW4egVKebbVdT2K0ua9sC+AJ62bG0/Lkzfcmo0njGPQ4Hn+8kwihjssuk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=R+yZYazj; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="R+yZYazj" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1734088207; 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=Uxy6mePHA2mFbKxl3XRp7ln++RG16/GzEJG31dpj1nE=; b=R+yZYazjGXgEtlAwCUoXkhdA0CHz8HfPaMsRYOinaxSvVmHcTjgRXd1I2kMayc2A1PZW28 1IIkqpFcWZqP/kvPiIq2NOVlawmYVs2W3vym912HwKOTMZgEPpFK0BWSut9EcXW94/6xym ZS9VH1MtRhXrb+rVm/+m1fGeDGfTzKo= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-60-GML14rjxNomuNcIIJA4JxQ-1; Fri, 13 Dec 2024 06:10:02 -0500 X-MC-Unique: GML14rjxNomuNcIIJA4JxQ-1 X-Mimecast-MFC-AGG-ID: GML14rjxNomuNcIIJA4JxQ Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 73631195608E; Fri, 13 Dec 2024 11:09:59 +0000 (UTC) Received: from fedora (unknown [10.72.116.91]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 88A1D1956086; Fri, 13 Dec 2024 11:09:47 +0000 (UTC) Date: Fri, 13 Dec 2024 19:09:41 +0800 From: Ming Lei To: Thomas Gleixner Cc: David Woodhouse , Stefan Hajnoczi , Jason Wang , "x86@kernel.org" , hpa , dyoung , kexec , linux-ext4 , "Michael S. Tsirkin" , Stefano Garzarella , eperezma , Paolo Bonzini , Petr Mladek , John Ogness , Peter Zijlstra , Jens Axboe Subject: Re: Lockdep warnings on kexec (virtio_blk, hrtimers) Message-ID: References: <20241211124240.GA310916@fedora> <7717fe2ac0ce5f0a2c43fdab8b11f4483d54a2a4.camel@infradead.org> <87ldwl9g93.ffs@tglx> <10f5d22150b548ec271e0a847ba2eb91139e6f61.camel@infradead.org> <87a5d0aibc.ffs@tglx> <874j38a16p.ffs@tglx> <9c4b189656a0a773227a11568171903989130bb7.camel@infradead.org> <871pybamoc.ffs@tglx> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871pybamoc.ffs@tglx> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 On Fri, Dec 13, 2024 at 11:42:59AM +0100, Thomas Gleixner wrote: > On Fri, Dec 13 2024 at 09:43, David Woodhouse wrote: > > On Fri, 2024-12-13 at 09:31 +0000, David Woodhouse wrote: > >> > >> (gdb) p sysrq_handle_showstate('t') > >> > >> That didn't work. Maybe if I'd actually had no_console_suspend on this > >> boot. Will try again. > > > > With your fix I get the same thing (both CPUs in idle thread). And with > > no_console_suspend on the command line, 'p sysrq_handle_showstate('t')' > > does work... > > > > [ 113.462898] task:loadret state:D stack:0 pid:707 tgid:707 ppid:531 flags:0x00004002 > > [ 113.463615] Call Trace: > > [ 113.463841] > > [ 113.464029] __schedule+0x502/0x1a10 > > [ 113.464961] schedule+0x3a/0x140 > > [ 113.465234] schedule_timeout+0xcc/0x110 > > [ 113.465580] __wait_for_common+0x91/0x1c0 > > [ 113.466304] cpuhp_kick_ap_work+0x13e/0x390 > > [ 113.466657] _cpu_down+0xd4/0x370 > > [ 113.466936] freeze_secondary_cpus.cold+0x3f/0xd4 > > [ 113.467326] kernel_kexec+0xa2/0x1a0 > > That's the control thread on CPU0. The hotplug thread on CPU1 is stuck > here: > > task:cpuhp/1 state:D stack:0 pid:24 tgid:24 ppid:2 flags:0x00004000 > Call Trace: > > __schedule+0x51f/0x1a80 > schedule+0x3a/0x140 > schedule_timeout+0x90/0x110 > msleep+0x2b/0x40 > blk_mq_hctx_notify_offline+0x160/0x3a0 > cpuhp_invoke_callback+0x2a8/0x6c0 > cpuhp_thread_fun+0x1ed/0x270 > smpboot_thread_fn+0xda/0x1d0 > > So something with those blk_mq fixes went sideways. The cpuhp callback is just waiting for inflight IOs to be completed when the irq is still live. It looks same with the following report: https://lore.kernel.org/linux-scsi/F991D40F7D096653+20241203211857.0291ab1b@john-PC/ Still triggered in case of kexec & qemu, which should be one qemu problem. Thanks, Ming