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 X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59606C433E7 for ; Tue, 20 Oct 2020 10:08:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 01A2E222E8 for ; Tue, 20 Oct 2020 10:08:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603188516; bh=Pvc6PAgxMsRidFxK+BBUIS16vHaM9gVploXYIngka3M=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=EsTVt2aZ+krBozvn7/BVP3qgM7ZDD8rKttyoX5Q6Cdo+c2Cy0w1Oka5i1Q7M9zybD QTtFrMg1hpsjym5wF1RZhaYjLljRa7CHw9Dks36+HrImOHZzrrlQk+XHsicUrVfcUp etBUlp9vpJHTkhSV2p7AYGmJnL2AyIey/0aCIVuo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405615AbgJTKIe (ORCPT ); Tue, 20 Oct 2020 06:08:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:37276 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730311AbgJTKIe (ORCPT ); Tue, 20 Oct 2020 06:08:34 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7244F22253; Tue, 20 Oct 2020 10:08:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603188513; bh=Pvc6PAgxMsRidFxK+BBUIS16vHaM9gVploXYIngka3M=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=D6ppd8bndAPKng3zkj9Ww196fvyQt4yzrHa3LIw7jYYRYGHudL6tm421CVeh7+Zmt Wxutd6ebNuX1lDfMzkevtg/IUB4e10tQjDHC/VxrkdZrfchw86qeIcO8symkAAeFsU Jj6PHQpMNS7Ok9aK6OUAfqwktAvUT6lsXtadtAkw= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1kUoZC-002gji-Vr; Tue, 20 Oct 2020 11:08:31 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Tue, 20 Oct 2020 11:08:30 +0100 From: Marc Zyngier To: Sumit Garg Cc: Catalin Marinas , Will Deacon , linux-arm-kernel , Thomas Gleixner , Jason Cooper , Mark Rutland , julien.thierry.kdev@gmail.com, Douglas Anderson , Daniel Thompson , Jason Wessel , Masayoshi Mizuma , ito-yuichi@fujitsu.com, kgdb-bugreport@lists.sourceforge.net, Linux Kernel Mailing List Subject: Re: [PATCH v5 1/5] arm64: Add framework to turn IPI as NMI In-Reply-To: References: <1602673931-28782-1-git-send-email-sumit.garg@linaro.org> <1602673931-28782-2-git-send-email-sumit.garg@linaro.org> User-Agent: Roundcube Webmail/1.4.9 Message-ID: X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: sumit.garg@linaro.org, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, tglx@linutronix.de, jason@lakedaemon.net, mark.rutland@arm.com, julien.thierry.kdev@gmail.com, dianders@chromium.org, daniel.thompson@linaro.org, jason.wessel@windriver.com, msys.mizuma@gmail.com, ito-yuichi@fujitsu.com, kgdb-bugreport@lists.sourceforge.net, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-10-20 07:43, Sumit Garg wrote: > On Mon, 19 Oct 2020 at 17:07, Marc Zyngier wrote: [...] >> > +{ >> > + if (!ipi_desc) >> > + return; >> > + >> > + if (is_nmi) { >> > + if (!prepare_percpu_nmi(ipi_id)) >> > + enable_percpu_nmi(ipi_id, IRQ_TYPE_NONE); >> > + } else { >> > + enable_percpu_irq(ipi_id, IRQ_TYPE_NONE); >> >> I'm not keen on this. Normal IRQs can't reliably work, so why do you >> even bother with this? > > Yeah I agree but we need to support existing functionality for kgdb > roundup and sysrq backtrace using normal IRQs as well. When has this become a requirement? I don't really see the point in implementing something that is known not to work. M. -- Jazz is not dead. It just smells funny...