Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965620AbdGTWHX (ORCPT ); Thu, 20 Jul 2017 18:07:23 -0400 Received: from relay1.sgi.com ([192.48.180.66]:32777 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936168AbdGTWHW (ORCPT ); Thu, 20 Jul 2017 18:07:22 -0400 From: Andrew Banman To: mingo@redhat.com Cc: Andrew Banman , tglx@linutronix.de, x86@kernel.org, linux-kernel@vger.kernel.org, rja@hpe.com, mike.travis@hpe.com, tony.ernst@hpe.com Subject: [PATCH v2] x86/platform/uv/BAU: disable BAU on single hub configurations Date: Thu, 20 Jul 2017 17:05:51 -0500 Message-Id: <1500588351-78016-1-git-send-email-abanman@hpe.com> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1500414693-84043-1-git-send-email-abanman@hpe.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2015 Lines: 68 The BAU confers no benefit to a UV system running with only one hub/socket. Permanently disable the BAU driver if there are less than two hubs online to avoid BAU overhead. We have observed failed boots on single-socket UV4 systems caused by BAU that are avoided with this patch. Version 2: Consolidate initialization error blocks with goto err_bau_disable and free the per_cpu cpumasks to fix a memory leak. Signed-off-by: Andrew Banman Acked-by: Russ Anderson Acked-by: Mike Travis --- arch/x86/platform/uv/tlb_uv.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c index 2511a28..e4a51a6 100644 --- a/arch/x86/platform/uv/tlb_uv.c +++ b/arch/x86/platform/uv/tlb_uv.c @@ -2245,13 +2245,17 @@ static int __init uv_bau_init(void) else if (is_uv1_hub()) ops = uv1_bau_ops; + nuvhubs = uv_num_possible_blades(); + if (nuvhubs < 2) { + pr_crit("UV: BAU disabled - insufficient hub count\n"); + goto err_bau_disable; + } + for_each_possible_cpu(cur_cpu) { mask = &per_cpu(uv_flush_tlb_mask, cur_cpu); zalloc_cpumask_var_node(mask, GFP_KERNEL, cpu_to_node(cur_cpu)); } - nuvhubs = uv_num_possible_blades(); - uv_base_pnode = 0x7fffffff; for (uvhub = 0; uvhub < nuvhubs; uvhub++) { cpus = uv_blade_nr_possible_cpus(uvhub); @@ -2264,9 +2268,8 @@ static int __init uv_bau_init(void) enable_timeouts(); if (init_per_cpu(nuvhubs, uv_base_pnode)) { - set_bau_off(); - nobau_perm = 1; - return 0; + pr_crit("UV: BAU disabled - per CPU init failed\n"); + goto err_bau_disable; } vector = UV_BAU_MESSAGE; @@ -2292,6 +2295,14 @@ static int __init uv_bau_init(void) } return 0; + +err_bau_disable: + for_each_possible_cpu(cur_cpu) { + free_cpumask_var(per_cpu(uv_flush_tlb_mask, cur_cpu)); + } + set_bau_off(); + nobau_perm = 1; + return -EINVAL; } core_initcall(uv_bau_init); fs_initcall(uv_ptc_init); -- 1.8.2.1