From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 CC5762746A; Tue, 29 Apr 2025 15:19:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745939955; cv=none; b=Lr71/8mUz21/msogWDMBQQjGf7ZMLRV71qaEMkCRuEse7ctS9Ozjq8vCb94cayIBFpFsrI+etDnwRzEUpmlXRjwSvmqknQEleYsqXppkM2IDj+423q4kGcAlx0LSSxh0MMWb7jIO3i5s99/vHHXA4iTD0ueUF9Vny4v2m5DdCFs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745939955; c=relaxed/simple; bh=3C8fhB1fGzK7l6qdXHOl1DpkXFliBZMpdfcLMqkBWl4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=oQqAZcsGzDrIhN+DZiFC4BMZEq8tXPX6Ho1I4enQlvGQ88nqD1LV2B7B4StmelRhn5fGHbvPSrqbsi6h3OB21IVQd9G0AAdm1HgBj0apNf47T7RmQS7+//r6S7gMf7+G99KoTwyuTk6HkNtSqMFsJildDkp83EtN8+q2GO1toeU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=fjuEtJt/; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="fjuEtJt/" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ylYybXRg8BOTls77x7I6uqAkR57DkifaGTI+lQneTd0=; b=fjuEtJt/emY2co4/t5cOHPVHMp 84aONTqApzZwB60TU2nF19qlPCxs+aw9FJi/ftyWpw+VsUF+w+NiqQVEvWGSmaC7zmWMA8eINsWNA rKd6XgeTudO5qZcpXrpMlFdeF6OghsQxq+P83Fc9OLjMCFswQWdSGKrdmTgLOSw4zBrU1LPuyt3bK nrL07kVqZGE589vMsiV32QGr1XH40JZA/FSQicrLARUJYnEAw3ec2OtmbuJGvrevIfH3iY2nV/Ahh nzDDzEmjf6LIIy2+NLmMMGXDizYIzVq5iq+j4yr6dmR0njUFBQ0wSUmh4OdJVDi9MXrjJTdmDAEOB qieQq3bg==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.1 #2 (Red Hat Linux)) id 1u9mjg-0000000DRBs-37cP; Tue, 29 Apr 2025 15:19:04 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id EAB1330035E; Tue, 29 Apr 2025 17:19:03 +0200 (CEST) Date: Tue, 29 Apr 2025 17:19:03 +0200 From: Peter Zijlstra To: Michael Kelley Cc: "x86@kernel.org" , "kys@microsoft.com" , "haiyangz@microsoft.com" , "wei.liu@kernel.org" , "decui@microsoft.com" , "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "dave.hansen@linux.intel.com" , "hpa@zytor.com" , "jpoimboe@kernel.org" , "pawan.kumar.gupta@linux.intel.com" , "seanjc@google.com" , "pbonzini@redhat.com" , "ardb@kernel.org" , "kees@kernel.org" , Arnd Bergmann , "gregkh@linuxfoundation.org" , "linux-hyperv@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "linux-efi@vger.kernel.org" , "samitolvanen@google.com" , "ojeda@kernel.org" Subject: Re: [PATCH 5/6] x86_64,hyperv: Use direct call to hypercall-page Message-ID: <20250429151903.GK4198@noisy.programming.kicks-ass.net> References: <20250414111140.586315004@infradead.org> <20250414113754.435282530@infradead.org> <20250425140355.GC35881@noisy.programming.kicks-ass.net> 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=us-ascii Content-Disposition: inline In-Reply-To: On Sun, Apr 27, 2025 at 03:58:54AM +0000, Michael Kelley wrote: > Indeed, control never returns from static_call_update(). Prior to > hyperv_cleanup() running, crash_smp_send_stop() has been called to > stop all the other CPUs, and it does not update cpu_online_mask to > reflect the other CPUs being stopped. > > static_call_update() runs this call sequence: > > arch_static_call_transform() > __static_call_transform() > smp_text_poke_single() > smp_text_poke_batch_finish() > smp_text_poke_sync_each_cpu() > > smp_text_poke_sync_each_cpu() sends an IPI to each CPU in > cpu_online_mask, and of course the other CPUs never respond, so > it waits forever. Fair enough. I'll just remove this final call. Thanks!