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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6FFCC63797 for ; Tue, 17 Jan 2023 08:28:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235980AbjAQI21 (ORCPT ); Tue, 17 Jan 2023 03:28:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235811AbjAQI2Y (ORCPT ); Tue, 17 Jan 2023 03:28:24 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DF8E122798 for ; Tue, 17 Jan 2023 00:27:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673944053; 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=gg7qkv1C1Ou83J3gkN1LzeHJIr1iBZFQETY1qPldk9s=; b=HaZlw81mSN4CIrkQQsHpNiCsU6f6iWVgOozE+dvURnCRh4eeXa3A187F9swC3zTAAPHW9t oWOInbgtqfOLOjCufpeRrty3YllwN3654h+qb0pYBsldaWzUtBRRuKls3aPkgde7ilx2T0 o6jUDDS1P3nrSCiFkC0i6nwVYGEN+vI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-270-nESQqZ6lMb2BsRB0SL1EKg-1; Tue, 17 Jan 2023 03:27:28 -0500 X-MC-Unique: nESQqZ6lMb2BsRB0SL1EKg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7D6D2858F09; Tue, 17 Jan 2023 08:27:28 +0000 (UTC) Received: from localhost (ovpn-12-229.pek2.redhat.com [10.72.12.229]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A5173C15BA0; Tue, 17 Jan 2023 08:27:27 +0000 (UTC) Date: Tue, 17 Jan 2023 16:27:23 +0800 From: Baoquan He To: Thomas Gleixner Cc: linux-kernel@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org Subject: Re: [PATCH] Revert "x86/apic/x2apic: Implement IPI shorthands support" Message-ID: References: <87k01vjrnt.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/10/23 at 10:24am, Baoquan He wrote: > On 01/09/23 at 10:59pm, Thomas Gleixner wrote: > > On Tue, Dec 20 2022 at 13:34, 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. > > > > Is there any output on the early console or hangs it silently? > > > > If the latter, can you attach GDB to the guest and figure out where it > > is stuck? > > No any output on the ealry console. I will try gdb debugging. Thanks. I rebase to the latest upstream kernel and tested, the stable kdump kernel hang disappear. Seems I need do another round of bisect to see on which commit it's made to fix that. Will update if any progress.