From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 41PT4N08dfzDr2p for ; Tue, 10 Jul 2018 00:58:59 +1000 (AEST) Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w69Erko8099461 for ; Mon, 9 Jul 2018 10:58:57 -0400 Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) by mx0a-001b2d01.pphosted.com with ESMTP id 2k499gjr81-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 09 Jul 2018 10:58:57 -0400 Received: from localhost by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 9 Jul 2018 08:58:56 -0600 From: Michael Bringmann Subject: [PATCH v06 6/9] pmt/numa: Disable arch_update_cpu_topology during CPU readd Cc: Michael Bringmann , Nathan Fontenot , John Allen , Tyrel Datwyler , Thomas Falcon To: linuxppc-dev@lists.ozlabs.org In-Reply-To: <4e6b3582-0033-b232-3769-226ba6f68eac@linux.vnet.ibm.com> Date: Mon, 9 Jul 2018 09:58:52 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Message-Id: List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , pmt/numa: Disable arch_update_cpu_topology during post migration CPU readd updates when evaluating device-tree changes after LPM to avoid thread deadlocks trying to update node assignments. System timing between all of the threads and timers restarted in a migrated system overlapped frequently allowing tasks to start acquiring resources (get_online_cpus) needed by rebuild_sched_domains. Defer the operation of that function until after the CPU readd has completed. Signed-off-by: Michael Bringmann --- arch/powerpc/platforms/pseries/hotplug-cpu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c index 8f28160..6267b53 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -26,6 +26,7 @@ #include /* for idle_task_exit */ #include #include +#include #include #include #include @@ -685,9 +686,15 @@ static int dlpar_cpu_readd_by_index(u32 drc_index) pr_info("Attempting to re-add CPU, drc index %x\n", drc_index); + arch_update_cpu_topology_suspend(); rc = dlpar_cpu_remove_by_index(drc_index, false); - if (!rc) + arch_update_cpu_topology_resume(); + + if (!rc) { + arch_update_cpu_topology_suspend(); rc = dlpar_cpu_add(drc_index, false); + arch_update_cpu_topology_resume(); + } if (rc) pr_info("Failed to update cpu at drc_index %lx\n",