From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 69416436377; Tue, 10 Mar 2026 09:00:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773133207; cv=none; b=ROjDj0avosEosB3WKwYsQyu+Ih7IOhw6rc63/k/nd0grxd+agCgUPxlemDyuRs/2uLoS2gBi+NoiGmaOL8flccjXeFs/rbDF1Wk7fw75i+AIHFQdWKgb3rrjszWH8NRreZF/M0Kc6u2UEfDj3s6Z3NYAfoGAJHZJFIbESbUzqo4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773133207; c=relaxed/simple; bh=bx403b/zRrbKVsyudjpDKxSmcDF0O3Ag34b2nfgC1jQ=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=MXMUyk6v+2w1+sE2hHCU6LUzYUyzndqBQqqlmDlvw9VoP9Y4Br+PlOBmvVpckSx+Hm7Sj3FGx++bGoc0ankCZskcfpTwgli+vQPhJy7wVNbBJTNct9RX8SAQ0orFDRPjY3l9Aqkxn5tWvimoR+w7OKuwfp5cAVjgQb+IK8GEU0M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UjfYJGaT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UjfYJGaT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C31BFC19423; Tue, 10 Mar 2026 09:00:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773133207; bh=bx403b/zRrbKVsyudjpDKxSmcDF0O3Ag34b2nfgC1jQ=; h=Date:Subject:From:To:Cc:References:In-Reply-To:From; b=UjfYJGaT36r5iqwTQs5p/a4GzNj9rwUkkMg9ynEkOW22RR+2pXqpRDNFEyLcYuaF/ 96fHUBIMf3gtm3BZhPLQk94N703UupLqiwGnPynyLS0HPDe2sdy3W4UhfgtCggHBPF f0qyIp+JCu5L0hrYwwUqjRp9hnVEVYTImlvXiWeyvG3PR8Hfl5URW5a79xJINbE3u6 aKWWEKvRcwj+IO20svoSOEkoz2wvmoT0YU9B+WUig8a6ZKJy2Oxh9+7kwskYH/etNl aljrMsFN3suDlT+Bj+TmBWx9oXxXiyH4mnyjDDzPutK5sav2NMnckpXFBBclhSLKyI BORFHt/xUq/OA== Message-ID: <76e2b909-98db-49de-a8eb-f6f0a192f630@kernel.org> Date: Tue, 10 Mar 2026 10:00:01 +0100 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Stalls when starting a VSOCK listening socket: soft lockups, RCU stalls, timeout From: Jiri Slaby To: Thomas Gleixner , Matthieu Baerts Cc: Peter Zijlstra , Stefan Hajnoczi , Stefano Garzarella , kvm@vger.kernel.org, virtualization@lists.linux.dev, Netdev , rcu@vger.kernel.org, MPTCP Linux , Linux Kernel , Shinichiro Kawasaki , "Paul E. McKenney" , Dave Hansen , luto@kernel.org, =?UTF-8?Q?Michal_Koutn=C3=BD?= , Waiman Long , Marco Elver References: <863a5291-a636-47d0-891c-bb0524d2e134@kernel.org> <20260302114636.GL606826@noisy.programming.kicks-ass.net> <717310d8-6274-4b7f-8a19-561c45f5f565@kernel.org> <87zf4m2qvo.ffs@tglx> <47cba228-bba7-4e58-a69d-ea41f8de6602@kernel.org> <87tsuu2i59.ffs@tglx> <7efde2b5-3b72-4858-9db0-22493d446301@kernel.org> <87qzpx2sck.ffs@tglx> <20260306152458.GT606826@noisy.programming.kicks-ass.net> <87ldg42eu7.ffs@tglx> <87h5qr2rzi.ffs@tglx> <87eclu3coa.ffs@tglx> <87v7f61cnl.ffs@tglx> <57c1e171-9520-4288-9e2d-10a72a499968@kernel.org> <87pl5ds88r.ffs@tglx> <0ae4d678-5676-4523-bae3-5ad73b526e27@kernel.org> <87eclsrtqg.ffs@tglx> Content-Language: en-US Autocrypt: addr=jirislaby@kernel.org; keydata= xsFNBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABzSFKaXJpIFNsYWJ5 IDxqaXJpc2xhYnlAa2VybmVsLm9yZz7CwXcEEwEIACEFAlW3RUwCGwMFCwkIBwIGFQgJCgsC BBYCAwECHgECF4AACgkQvSWxBAa0cEnVTg//TQpdIAr8Tn0VAeUjdVIH9XCFw+cPSU+zMSCH eCZoA/N6gitEcnvHoFVVM7b3hK2HgoFUNbmYC0RdcSc80pOF5gCnACSP9XWHGWzeKCARRcQR 4s5YD8I4VV5hqXcKo2DFAtIOVbHDW+0okOzcecdasCakUTr7s2fXz97uuoc2gIBB7bmHUGAH XQXHvdnCLjDjR+eJN+zrtbqZKYSfj89s/ZHn5Slug6w8qOPT1sVNGG+eWPlc5s7XYhT9z66E l5C0rG35JE4PhC+tl7BaE5IwjJlBMHf/cMJxNHAYoQ1hWQCKOfMDQ6bsEr++kGUCbHkrEFwD UVA72iLnnnlZCMevwE4hc0zVhseWhPc/KMYObU1sDGqaCesRLkE3tiE7X2cikmj/qH0CoMWe gjnwnQ2qVJcaPSzJ4QITvchEQ+tbuVAyvn9H+9MkdT7b7b2OaqYsUP8rn/2k1Td5zknUz7iF oJ0Z9wPTl6tDfF8phaMIPISYrhceVOIoL+rWfaikhBulZTIT5ihieY9nQOw6vhOfWkYvv0Dl o4GRnb2ybPQpfEs7WtetOsUgiUbfljTgILFw3CsPW8JESOGQc0Pv8ieznIighqPPFz9g+zSu Ss/rpcsqag5n9rQp/H3WW5zKUpeYcKGaPDp/vSUovMcjp8USIhzBBrmI7UWAtuedG9prjqfO wU0ETpLnhgEQAM+cDWLL+Wvc9cLhA2OXZ/gMmu7NbYKjfth1UyOuBd5emIO+d4RfFM02XFTI t4MxwhAryhsKQQcA4iQNldkbyeviYrPKWjLTjRXT5cD2lpWzr+Jx7mX7InV5JOz1Qq+P+nJW YIBjUKhI03ux89p58CYil24Zpyn2F5cX7U+inY8lJIBwLPBnc9Z0An/DVnUOD+0wIcYVnZAK DiIXODkGqTg3fhZwbbi+KAhtHPFM2fGw2VTUf62IHzV+eBSnamzPOBc1XsJYKRo3FHNeLuS8 f4wUe7bWb9O66PPFK/RkeqNX6akkFBf9VfrZ1rTEKAyJ2uqf1EI1olYnENk4+00IBa+BavGQ 8UW9dGW3nbPrfuOV5UUvbnsSQwj67pSdrBQqilr5N/5H9z7VCDQ0dhuJNtvDSlTf2iUFBqgk 3smln31PUYiVPrMP0V4ja0i9qtO/TB01rTfTyXTRtqz53qO5dGsYiliJO5aUmh8swVpotgK4 /57h3zGsaXO9PGgnnAdqeKVITaFTLY1ISg+Ptb4KoliiOjrBMmQUSJVtkUXMrCMCeuPDGHo7 39Xc75lcHlGuM3yEB//htKjyprbLeLf1y4xPyTeeF5zg/0ztRZNKZicgEmxyUNBHHnBKHQxz 1j+mzH0HjZZtXjGu2KLJ18G07q0fpz2ZPk2D53Ww39VNI/J9ABEBAAHCwV8EGAECAAkFAk6S 54YCGwwACgkQvSWxBAa0cEk3tRAAgO+DFpbyIa4RlnfpcW17AfnpZi9VR5+zr496n2jH/1ld wRO/S+QNSA8qdABqMb9WI4BNaoANgcg0AS429Mq0taaWKkAjkkGAT7mD1Q5PiLr06Y/+Kzdr 90eUVneqM2TUQQbK+Kh7JwmGVrRGNqQrDk+gRNvKnGwFNeTkTKtJ0P8jYd7P1gZb9Fwj9YLx jhn/sVIhNmEBLBoI7PL+9fbILqJPHgAwW35rpnq4f/EYTykbk1sa13Tav6btJ+4QOgbcezWI wZ5w/JVfEJW9JXp3BFAVzRQ5nVrrLDAJZ8Y5ioWcm99JtSIIxXxt9FJaGc1Bgsi5K/+dyTKL wLMJgiBzbVx8G+fCJJ9YtlNOPWhbKPlrQ8+AY52Aagi9WNhe6XfJdh5g6ptiOILm330mkR4g W6nEgZVyIyTq3ekOuruftWL99qpP5zi+eNrMmLRQx9iecDNgFr342R9bTDlb1TLuRb+/tJ98 f/bIWIr0cqQmqQ33FgRhrG1+Xml6UXyJ2jExmlO8JljuOGeXYh6ZkIEyzqzffzBLXZCujlYQ DFXpyMNVJ2ZwPmX2mWEoYuaBU0JN7wM+/zWgOf2zRwhEuD3A2cO2PxoiIfyUEfB9SSmffaK/ S4xXoB6wvGENZ85Hg37C7WDNdaAt6Xh2uQIly5grkgvWppkNy4ZHxE+jeNsU7tg= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 10. 03. 26, 9:56, Jiri Slaby wrote: > Thomas, > > On 10. 03. 26, 9:09, Thomas Gleixner wrote: >>     2) task is not longer in the task list w/o going through do_exit() > > After a quick look (I have to run now, so I could be completely wrong): > what about the task is not in the list *yet*. You use RCU -> > for_each_process_thread(), so there could be a race with attach_pid() > protected by tasklist_lock. Not attach_pid(), that's irrelevant here. But one line below in copy_process(): list_add_tail(). > thanks, -- js suse labs