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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 418CBC432C0 for ; Tue, 19 Nov 2019 06:05:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0D5CB2082F for ; Tue, 19 Nov 2019 06:05:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574143553; bh=COVWsDCNKbR38Yw+05vHLBxceN6cUCoS+2GIdiYO/IE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qsF8bDoIPtoFr774SUbFVgFFG6WnND7EWCa7JdbJty6+LCt6RioVL4euLOeo/gQJq UcchYsEjYA34Qz8KhDRSeimXYvJHBOXS/kTFX91kgUrUTD1otKSJh0EeB3DAZqBNPk 1fCUfdhY14EwPCE4wR3DbZNUY2V0EZfhEQjkTluQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729845AbfKSFfs (ORCPT ); Tue, 19 Nov 2019 00:35:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:56742 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728370AbfKSFfq (ORCPT ); Tue, 19 Nov 2019 00:35:46 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DD77B20862; Tue, 19 Nov 2019 05:35:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574141745; bh=COVWsDCNKbR38Yw+05vHLBxceN6cUCoS+2GIdiYO/IE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mCiTWyp0g4/jRW1HfbRpPopYZVaePxioQFuQlh00dkaOmad/K0S9J15hF9UG0D2yC FWJ93OGksyYATiookJyEtHOWbXnA6vMwlKfUJpKB7dl2lplvoQdjDArkkV413VHyD2 vp/IQ9oaFo5YheqqKO33sLZmM1l4y1NHPw5SQEK0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nathan Fontenot , Tyrel Datwyler , Michael Ellerman , Sasha Levin Subject: [PATCH 4.19 264/422] powerpc/pseries: Disable CPU hotplug across migrations Date: Tue, 19 Nov 2019 06:17:41 +0100 Message-Id: <20191119051416.098423218@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191119051400.261610025@linuxfoundation.org> References: <20191119051400.261610025@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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