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 2073C255240 for ; Thu, 24 Jul 2025 09:36:14 +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=1753349777; cv=none; b=euj8TjZLal2jOPwdPXfdqM97Rx693UrzGtnCOSAIDT1aAQp/SethVSMHST4FOadm1VtfpVDG3JKMhVI5YO+Ifv8PPTKtUHU4c4F0rv3Xkx1fuiPlhzp3/h/IeU5tbZgvz3rT6yYELmJtl1hQOZchkIaHYpNFq7OGLhorN7Blg3o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753349777; c=relaxed/simple; bh=ztMo+M1ZYiDY8s1Tm47cuFM5eK9wC8+ZbhC6nC/Dt+I=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=mPoSsFfvGPghGGfp7EQvZGdTNYbC+/8khCqAAXGr8aWtxgpua7XQJypRlg48by3OzsiOOw/QR4EPMITeziVnEAAAEVBLGtEzJvwOIM7wG0DgXXlqsgMf7H5ZUU3jH3vNMG90ff5DPeO50p9okGa5jBjhxdhT5u4foYDpj/sSHFI= 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=pVZZPOr9; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=lD0kXarl; 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="pVZZPOr9"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="lD0kXarl" From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1753349772; 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=St8LhG2IloKI6vEQFWiwV2Hz249Z2tbERnS7qMqFGAg=; b=pVZZPOr9b6yTr0WuswDzGYj3d6rmPl/w8kTksCuV26YvOnmesRfdlxcX56+8qXm2dhCtRo T2nBFfCGslePZ4xosDsvpFges80puq8TMZjDOC89Fwred0w3x25SZyfbyQtUmz+jH57vvF QdBSeX+T65CBn//1KT7oPDtIsAgrH+LHr52os4mqjOp+qwXVNfibvXedeqrvvwyPjq+a2x R3U9PJmuO1mNlBmA74kjIH6OWcutf/gtLvPP1lNfi1XqSkIABra34Iqzfvo4piw1bTHkcJ lD0BnpA/N/txY1puyl/x//KPF+lw9rKDICfWqR6Oa09/CIqpJbE8hhgvtjc5iQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1753349772; 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=St8LhG2IloKI6vEQFWiwV2Hz249Z2tbERnS7qMqFGAg=; b=lD0kXarl+6KbeLP2BNsNQyKFeU14dOCFegu7UAE/z6llVEzD3/ehWdjEPhl0A0BGZkMogw RDfLO6rCnKMrOwAg== To: =?utf-8?B?6IOh54Sc?= Cc: =?utf-8?B?55m954OB5YaJ?= , Peter Zijlstra , "jjtan24@m.fudan.edu.cn" , linux-kernel@vger.kernel.org Subject: Re: possible deadlock in smp_call_function_many_cond In-Reply-To: References: <758991c1.13f67.197f9cccf9b.Coremail.baishuoran@hrbeu.edu.cn> <877c02vejr.ffs@tglx> Date: Thu, 24 Jul 2025 11:35:59 +0200 Message-ID: <87o6taq6bk.ffs@tglx> 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-Transfer-Encoding: quoted-printable On Thu, Jul 24 2025 at 15:55, =E8=83=A1=E7=84=9C wrote: Please do not top-post and trim your replies: https://people.kernel.org/tglx/notes-about-netiquette > My guess is that the crash point might be csd_lock_wait(csd) in > ~/kernel/smp.c on line 885. Here the other CPUs are notified via IPI > to execute flush_tlb_mm_range and enter spin wait. However, it has not > yet been determined which CPU performed the operation that caused the > IPI to return a timeout. Guessing is not a proper engineering method :) > I'll first provide the log that was reproduced in 6.16-rc4. we'll re-veri= fy it on rc7. > [ 0.000000][ T0] Linux version 6.16.0-rc4 (qjj@qjj-Standard-PC-Q35-= ICH9-2009) (gcc (Ubuntu 9.4.0-1ubuntu1~20.04.2) 9.4.0, GNU ld (GNU Binutils= for Ubuntu) 2.34) #1 SMP PREEMPT_DYNAMIC Wed Jul 2 09:53:03 CST 2025 > > [ 0.000000][ T0] Command line: root=3D/dev/sda console=3DttyS0 ftra= ce_dump_on_oops hrtimer_expire_entry hrtimer_expire_exit trace_event=3Dipi_= entry,ipi_exit,irq_handler_entry,irq_handler_exit Please remove the silly extra new-lines next time. > > [ 0.427302][ T0] Unknown kernel command line parameters "hrtimer_ex= pire_entry hrtimer_expire_exit spec_store_bypass_disable=3Dprctl nbds_max= =3D32", will be passed to user space. ^^^^^^^^^^= ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ How is this helpful?