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 5A84BC4332F for ; Tue, 20 Dec 2022 11:39:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=USvWLFWQUXbgTelTGfw5yMDPCPB9fMZaBdG2clwOltQ=; b=FztXixvM6vEgxV oq2SCi/Aa6Vap2fRioT7orAym+EUFjjGqN70NCzUmR1/IycyeEVhkZkwSe+jzz7MCMsFliccFe3O1 Q4a+F5K5fsEqZZgh9va0DTlHyTrniD3XU2cQYM+UFd0hsy4M378yPffeb6Qa0gWYXawh7fwYQNx8m NNIxJhFGn9szaX/c9+q5FawUMv2PbP5an6RisPU56naigWwWU3L30lS1IFsQepCFu0DQ0yIh7m8Yx ruotI2mX6dU3ODMHIkjDGyCM5hWGRaSmQUnEU4h/rfv47gv4O6OkbGngS7E20HYNES4S5GJd2/nP3 bdd7cenXmqWdUWdReV9g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p7axf-00DxeN-CB; Tue, 20 Dec 2022 11:39:07 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p7axQ-00DxVh-AG for kexec@bombadil.infradead.org; Tue, 20 Dec 2022 11:38:52 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=t89MKrBwUBLS+ByzcZGzZZQEQJcYQVoYJCazuvi3KIQ=; b=EAe87txzRGIH62QagEKuf9gafY x965J8pybTHj1rp6tKY8G9ajKrYYFbG3HvN7WsDG7U61sApoWul5/WISscm0GoO4jK0XNyAnH1nC4 3oIZ85eNPc/j2mSW+Fbm/1O9Im+FtlHNIizu7LMNQQ6QMIeKOafsReKYwdUIniMC1/BCdYFgJTsdZ OaTFDf5b8up5FSRNCSs1FSA0inFoQlbD6V2miDtEsND2LAQgZBpBohUKPy92lE6FT1WkrJIWODbAF sFrhCxHFrzdsawFQdaXbnY+d7VxoLG5VcHTUP+KlQOXmZky+C2KHJI2np255QxfjQQXnmc9HzTD2p pjxiN2Cg==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1p7axW-001kai-Jc; Tue, 20 Dec 2022 11:38:58 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 31E54300E86; Tue, 20 Dec 2022 12:38:47 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 12EAE20B0F896; Tue, 20 Dec 2022 12:38:47 +0100 (CET) Date: Tue, 20 Dec 2022 12:38:46 +0100 From: Peter Zijlstra To: Baoquan He Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , x86@kernel.org, kexec@lists.infradead.org Subject: Re: [PATCH] Revert "x86/apic/x2apic: Implement IPI shorthands support" Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On Tue, Dec 20, 2022 at 01:34:58PM +0800, Baoquan He wrote: > This reverts commit 43931d350f30c6cd8c2f498d54ef7d65750abc92. > > On kvm guest with 4 cpus deployed, when adding 'nr_cpus=2' to normal > kernel's cmdline, and triggering crash to jump to kdump kernel, kdump > kernel will stably hang. Reverting commit 43931d350f30 ("x86/apic/x2apic: > Implement IPI shorthands support") can fix it. > > The problem will disappear if removing 'nr_cpus=2' from normal kerne's > cmdline. And the root cause for this is... ? Does the kvm x2apic emulation somehow get upset when we shorthand CPUs that haven't been initialized? _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec