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 A46AFC4332F for ; Thu, 22 Dec 2022 04:09:31 +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=QmA2XAwHQ+yl2NlbDAtr2SGE5u8hvtb1y+sObpJWq+w=; b=MyIdq1+QvwH/ME cSz4Ot4o0iWumXsQ9U1tSmGqt/chMgE4yICwERweHsMCK7tJO4dtmKWtE8rgMuBQSIMEWHQ3bTQQC cNdQUs8i89ebfWKzAF79mUJGrg37rwSWmVPBh+/sBr79hFkmvoq3SfMIJKTN6rqqR/nGGz6CnRtqK YufhsAyiARCL2JYP5e+Q+PMulJuR3/hSlUL9mWXcBcgQxXHoySsfWhttZ3d9609eC902ch4PqcaNr 3tPgIzy0BUXvoL88oS7qaQKwzmaiybpj2AP16U9mV4JU5sJ4IgEu0bsyQ58MfW7OTJ+irFbYb1Aqs EmkEuhl3ISZiUsOMMvKA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p8CtV-006hdl-O4; Thu, 22 Dec 2022 04:09:21 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p8CtS-006hbv-7K for kexec@lists.infradead.org; Thu, 22 Dec 2022 04:09:20 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1671682157; 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=PZyafQqgBt7zn6f3VZzK00nebPDqAfKuXzcWmeIT/HE=; b=Sss3xcZAifRQE1MVmny532vIAwsFjwzzFpu20UsBHe6oFwBh2B9bW5rIgEGbpnkyq/DJlN YiUhKJk8r/pqc5hTZz9+wgA9mD42GqM8tLBOwj90Oig86OEm4CqeFcPmaLXunT8nHu2Yd2 dkqkJo9J8RHrrIMoHBlBC/6ElXf95Yc= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-152-8zmO4qUJPZen_wuY0c0Plg-1; Wed, 21 Dec 2022 23:09:13 -0500 X-MC-Unique: 8zmO4qUJPZen_wuY0c0Plg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id BA7311C02D35; Thu, 22 Dec 2022 04:09:09 +0000 (UTC) Received: from localhost (ovpn-12-50.pek2.redhat.com [10.72.12.50]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1672151E5; Thu, 22 Dec 2022 04:09:08 +0000 (UTC) Date: Thu, 22 Dec 2022 12:09:05 +0800 From: Baoquan He To: "Guilherme G. Piccoli" Cc: x86@kernel.org, kexec@lists.infradead.org, Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: kdump kernel randomly hang with tick_periodic call trace on bare metal system Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221221_200918_387063_9921A08C X-CRM114-Status: GOOD ( 17.31 ) 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 12/21/22 at 12:46pm, Guilherme G. Piccoli wrote: > On 20/12/2022 02:51, Baoquan He wrote: > > On 12/20/22 at 01:41pm, Baoquan He wrote: > >> On one intel bare metal system, I can randomly reproduce the kdump hang > >> as below with tick_periodic call trace. Attach the kernel config for > >> reference. > > > > Forgot mentioning this random hang is also caused by adding > > 'nr_cpus=2' into normal kernel's cmdline, then triggering crash will get > > kdump kernel hang as below kdump log shown. > > > > The weird thing is that you seem to be using "nr_cpus=1" instead - this > is the cmdline from the log: > > "nr_cpus=2 irqpoll nr_cpus=1 reset_devices cgroup_disable=memory mce=off > numa=off udev.children-max=2 panic=10 acpi_no_memhotplug > transparent_hugepage=never nokaslr hest_disable novmcoredd cma=0 > hugetlb_cma=0 disable_cpu_apicid=16 [...]" > > You seems to pass twice the "nr_cpus" thing, and I guess kernel pick the > last one? >From the kdump kernel boot log, yes, the nr_cpus=1 is taken. The parse_early_param() will parse the kernel parameters one by one, then the last one will take effect. Here, the problem is not at nr_cpus=2 or 1, the bare metal system has 16 cpus, only 2 cpus is present, it seems to be the halted 14 cpus get wrong message and behave incorrectly to cause the issue. > > Also, what is "disable_cpu_apicid=16"? Could this be related? Not really. Please check disable_cpu_apicid in Documentation/admin-guide/kdump/kdump.rst, it's bsp's apic id. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec