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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 5DEF5C17443 for ; Sun, 10 Nov 2019 03:16:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2640320854 for ; Sun, 10 Nov 2019 03:16:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573355798; bh=COVWsDCNKbR38Yw+05vHLBxceN6cUCoS+2GIdiYO/IE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JO3GgEvxoAaTZtqzNncjJxVQ287LX6S8gBxjLiNaz19STLTZeHlC3bBn7PtOHyyW+ GSYk2NKgmx6oVaqrtjX5ojnnU+Tc0gEBOAdsReBAbpRujzO8z7UwZE8mNjg6tiH1lv cZsDzGOlo4IJaB2I+SzzcTbEmGkIUmZBKvRomDaY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727429AbfKJDQ3 (ORCPT ); Sat, 9 Nov 2019 22:16:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:34604 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727137AbfKJCk4 (ORCPT ); Sat, 9 Nov 2019 21:40:56 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BF8B0215EA; Sun, 10 Nov 2019 02:40:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573353656; bh=COVWsDCNKbR38Yw+05vHLBxceN6cUCoS+2GIdiYO/IE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=En4ZCbQunj0rTnalbr4gdE+QpPIiZ9LIRAGAPGKJ/HebMz/WPYd4ynkBAdvzd5JbG W5gm/3QN4TNT4q7tc3h3wxACg3SrgFq/v++Qb3L8J8soAVdA+kyd2V94SN12ottXuX FkPn2HGlRmJxXabotcBMistj70npvPhO3WiLGiyI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nathan Fontenot , Tyrel Datwyler , Michael Ellerman , Sasha Levin , linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 4.19 030/191] powerpc/pseries: Disable CPU hotplug across migrations Date: Sat, 9 Nov 2019 21:37:32 -0500 Message-Id: <20191110024013.29782-30-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191110024013.29782-1-sashal@kernel.org> References: <20191110024013.29782-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nathan Fontenot [ Upstream commit 85a88cabad57d26d826dd94ea34d3a785824d802 ] When performing partition migrations all present CPUs must be online as all present CPUs must make the H_JOIN call as part of the migration process. Once all present CPUs make the H_JOIN call, one CPU is returned to make the rtas call to perform the migration to the destination system. During testing of migration and changing the SMT state we have found instances where CPUs are offlined, as part of the SMT state change, before they make the H_JOIN call. This results in a hung system where every CPU is either in H_JOIN or offline. To prevent this this patch disables CPU hotplug during the migration process. Signed-off-by: Nathan Fontenot Reviewed-by: Tyrel Datwyler Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin --- arch/powerpc/kernel/rtas.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index 9e41a9de43235..95d1264ba7952 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -985,6 +985,7 @@ int rtas_ibm_suspend_me(u64 handle) goto out; } + cpu_hotplug_disable(); stop_topology_update(); /* Call function on all CPUs. One of us will make the @@ -999,6 +1000,7 @@ int rtas_ibm_suspend_me(u64 handle) printk(KERN_ERR "Error doing global join\n"); start_topology_update(); + cpu_hotplug_enable(); /* Take down CPUs not online prior to suspend */ cpuret = rtas_offline_cpus_mask(offline_mask); -- 2.20.1