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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 8935BC433EF for ; Sat, 14 May 2022 14:05:04 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4L0nMf4D2pz3cL7 for ; Sun, 15 May 2022 00:05:02 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=LHg9QKXY; dkim=fail reason="signature verification failed" header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=Wccmxkq4; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linutronix.de (client-ip=2a0a:51c0:0:12e:550::1; helo=galois.linutronix.de; envelope-from=tglx@linutronix.de; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=LHg9QKXY; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=Wccmxkq4; dkim-atps=neutral Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4L0nLy1kSkz3bbs for ; Sun, 15 May 2022 00:04:26 +1000 (AEST) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1652537058; 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: in-reply-to:in-reply-to:references:references; bh=KHOIys2lUf5zRjBsSOUOWEZGDpRLn7fWHLTsPdw7f4U=; b=LHg9QKXYPrV5G6DpjGAQUj+qfPDVnxCZetHDBfVfH+LeqCXHlJAbKb8WllnreP7S3bNkfN 4KeQuJ7ASL57SIcHW5e0/ESjXmm27lFLndKPfS7ueia9+AnyVBizDI/I8cVvjyBodAV73C KuR6VX1IdjUZkcx7JJgKy1PXR652V3bzFUHb8gWx45QdbM32XdC1pSbLSU5kSVZNHK9CnN sYrvtcF6hGd4esjm7UwZp0Jjc3XOn+pTPW63vJAVYDRvjZI2qtcicolrLDuGi3y01KBsGF OHVzd6Qv0y0sYGOnTDmWoNHy2dKwZHGvbkDMdo4G48fllgMyGiB+2V0HQQZJAA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1652537058; 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: in-reply-to:in-reply-to:references:references; bh=KHOIys2lUf5zRjBsSOUOWEZGDpRLn7fWHLTsPdw7f4U=; b=Wccmxkq4ead+q0uv0ac7dDXkCM4gzRqejs0vLHNPNyx0+CzSuVgKfK7pCPPycJh8YJUxj4 LicVDTm3UgM/NtDA== To: Ricardo Neri Subject: Re: [PATCH v6 22/29] x86/watchdog/hardlockup: Add an HPET-based hardlockup detector In-Reply-To: <20220513221650.GA8691@ranerica-svr.sc.intel.com> References: <20220506000008.30892-1-ricardo.neri-calderon@linux.intel.com> <20220506000008.30892-23-ricardo.neri-calderon@linux.intel.com> <877d6uref8.ffs@tglx> <20220513221650.GA8691@ranerica-svr.sc.intel.com> Date: Sat, 14 May 2022 16:04:17 +0200 Message-ID: <875ym8rz1a.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Ravi V. Shankar" , Andi Kleen , linuxppc-dev@lists.ozlabs.org, Joerg Roedel , x86@kernel.org, Ricardo Neri , Stephane Eranian , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Tony Luck , Nicholas Piggin , Suravee Suthikulpanit , Andrew Morton , David Woodhouse , Lu Baolu Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Fri, May 13 2022 at 15:16, Ricardo Neri wrote: > On Mon, May 09, 2022 at 04:03:39PM +0200, Thomas Gleixner wrote: >> > + /* If we are here, IPI shorthands are enabled. */ >> > + apic->send_IPI_allbutself(NMI_VECTOR); >> >> So if the monitored cpumask is a subset of online CPUs, which is the >> case when isolation features are enabled, then you still send NMIs to >> those isolated CPUs. I'm sure the isolation folks will be enthused. > > Yes, I acknowledged this limitation in the cover letter. I should also update > Documentation/admin-guide/lockup-watchdogs.rst. > > This patchset proposes the HPET NMI watchdog as an opt-in feature. > > Perhaps the limitation might be mitigated by adding a check for non-housekeeping > and non-monitored CPUs in exc_nmi(). However, that will not eliminate the > problem of isolated CPUs also getting the NMI. Right. It's a mess...