From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AE22FC43458 for ; Thu, 9 Jul 2026 16:16:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jF3qVdoEbsJ3VzaNGIP2qIoT+ymr1N9tdwI2e6ZvOkg=; b=evjnYhpbpjUJtImZjqhph2JRNF m7n7hH75YYZUXtDfiTiXJnHnTqOV6SgF/vSnFoodkQJij73gEqBhgivc65HZZWvIn1moaauGz93i/ q7JM11RR1IoddJcq2tAFssP0DSLxPgjUgIppyifw24Joo6hPQ/slMiq89bmIeJF9HTMJWGs3P0XZH 8dkkhcLN2MTuEgGddkwaCmfkzObp26t/hM3LmzemoiZACh62JKAEhv9KV+Yui+eEfIrUZMrDJi3H9 SjoEFk6gQOPOrNpn6TShZdGfFNsz76zN57CZPeW8pSRAVHW+sbUcVRFe0nCx+Nq97oODF1ITxy17R Ly8U7cgg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1whrQX-000000030pk-3CjE; Thu, 09 Jul 2026 16:16:41 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1whrQW-000000030pY-3toe for linux-arm-kernel@lists.infradead.org; Thu, 09 Jul 2026 16:16:40 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id A8B464138E; Thu, 9 Jul 2026 16:16:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EF2821F00A3D; Thu, 9 Jul 2026 16:16:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783613800; bh=jF3qVdoEbsJ3VzaNGIP2qIoT+ymr1N9tdwI2e6ZvOkg=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=cwqDa2IxeR0ZYP/wu5gKBeyTyRvlGwRx7Rk1MI3pBXOKgl4hJpHOtOwOPfwza3mhp cFRHLJdSMHDWrXbFplOpVLDBgVxJikMF+l/ENcjsgI+K3xCJuyQBYQ/t2GDborCExl I2qysaFBQzMSMpsAo1CB5BLpZhkPF9NEMfNt6FoppGe1i+8D5GLoMuEHn17SOMMJ2o YgnTJhtGtdSF88NJeMBYUfczAn8ONGhajyUYCT8edBCJmtyAh2aed8Y/eqhEpJpJLa XsrInqpL+URkrBV7+hvirOI3IuvbegQ6XVj2C9JkwSLWL2G5UTmDdJSSei5RUnJ7ca mC2vvZkI2l4QQ== Received: from phl-compute-09.internal (phl-compute-09.internal [10.202.2.49]) by mailfauth.phl.internal (Postfix) with ESMTP id 25189F40090; Thu, 9 Jul 2026 12:16:39 -0400 (EDT) Received: from phl-frontend-04 ([10.202.2.163]) by phl-compute-09.internal (MEProxy); Thu, 09 Jul 2026 12:16:39 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: dmFkZTGWKpMVRfOvlVssIt8V4+GvxgmrUAKUiXyQp/UngjyA1pSIcf5yG8LmtmhOSgjUSq a6qFev133morqnN+20kiSDmMcxuiGTjw74LonpIDBKD/tealNzs7h4fe//+qO6X/LEdcTh mQTChkxWkwC8iUstLPTvsDASJHxTKg1pJdqU388/AuVgOJhqerONrNAww4agu7IiipIZb1 xSc5/cFZlRPwEgdZJ30QZhO0+2XElCXPwoK37BcBCsm9TUnSCqjnO+ZRbYMoF6ldnaQTDX XoB5k6HuHPNdtiP/PzhhnbVI4Qa0J0dCeopBse9ZparPe/OTvyFI6qCOgPhxSoAR2xsGFH akp5KNVf1nvr/ekmWN9zNXJCy+GCMidjd4CpQz/DEeLQNCoiW+Y85tBIXOJ8gERNQILE3k 0P/aMv6zFBg3XFWjxRn7/NEL34re6KlmmooBI8B2a491iUKaAjZia0apSBz+Exl+2sDaYI SFVIFBshyD53XxHTnHhj1xt6wUhMlDMghw0XYe5bNt5Nio7DBvI/uy0f6HKnXdRuG2LbIs 7RHcAH+NAc+oIG5ICT/Wu+B6hRx7YI5EHzyYnnngNESPlDcXPbgbMZevr+47APXx27IXp/ +S5zzWfhTZOZBPNe14PeSwXOmkKHi6qLuundoWzZgMp0n1+9Z7Z90IBCaaOw X-ME-Proxy: Feedback-ID: i10464835:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 9 Jul 2026 12:16:38 -0400 (EDT) Date: Thu, 9 Jul 2026 17:16:37 +0100 From: Kiryl Shutsemau To: Catalin Marinas , Will Deacon , James Morse Cc: Mark Rutland , Marc Zyngier , Doug Anderson , Petr Mladek , Thomas Gleixner , Andrew Morton , Baoquan He , Puranjay Mohan , Usama Arif , Breno Leitao , Julien Thierry , Lecopzer Chen , Sumit Garg , kernel-team@meta.com, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 0/4] arm64: cross-CPU NMI via SDEI Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Jun 29, 2026 at 04:07:14PM +0100, Kiryl Shutsemau wrote: > From: "Kiryl Shutsemau (Meta)" > > A class of debug/observability features needs to interrupt a CPU that has > its interrupts locally masked: the all-CPU backtrace behind sysrq-l / > RCU-stall / hung-task / hard-lockup dumps, and crash_smp_send_stop() > capturing a stuck CPU's state into the vmcore. On arm64 these need a > mechanism that reaches a CPU spinning with DAIF masked, which a normal IPI > cannot. Gentle ping. Any feedback? I'm looking forward to finding an upstreamable solution to the problem. -- Kiryl Shutsemau / Kirill A. Shutemov