From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicholas Piggin Subject: [PATCH v2 4/5] kernel/sched/isolation: require a present CPU in housekeeping mask Date: Thu, 11 Apr 2019 13:34:47 +1000 Message-ID: <20190411033448.20842-5-npiggin@gmail.com> References: <20190411033448.20842-1-npiggin@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190411033448.20842-1-npiggin@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Thomas Gleixner , Frederic Weisbecker Cc: Nicholas Piggin , Ingo Molnar , Peter Zijlstra , "Rafael J . Wysocki" , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org List-Id: linux-arch.vger.kernel.org During housekeeping mask setup, currently a possible CPU is required. That does not guarantee the CPU would be available at boot time, so check to ensure that at least one present CPU is in the mask. Signed-off-by: Nicholas Piggin --- kernel/sched/isolation.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index b02d148e7672..687302051a27 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -65,6 +65,7 @@ void __init housekeeping_init(void) static int __init housekeeping_setup(char *str, enum hk_flags flags) { cpumask_var_t non_housekeeping_mask; + cpumask_var_t tmp; int err; alloc_bootmem_cpumask_var(&non_housekeeping_mask); @@ -75,16 +76,23 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) return 0; } + alloc_bootmem_cpumask_var(&tmp); if (!housekeeping_flags) { alloc_bootmem_cpumask_var(&housekeeping_mask); cpumask_andnot(housekeeping_mask, cpu_possible_mask, non_housekeeping_mask); - if (cpumask_empty(housekeeping_mask)) + + cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask); + if (cpumask_empty(tmp)) { + pr_warn("Housekeeping: must include one present CPU, " + "using boot CPU:%d\n", smp_processor_id()); __cpumask_set_cpu(smp_processor_id(), housekeeping_mask); + __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask); + } } else { - cpumask_var_t tmp; - - alloc_bootmem_cpumask_var(&tmp); + cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask); + if (cpumask_empty(tmp)) + __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask); cpumask_andnot(tmp, cpu_possible_mask, non_housekeeping_mask); if (!cpumask_equal(tmp, housekeeping_mask)) { pr_warn("Housekeeping: nohz_full= must match isolcpus=\n"); @@ -92,8 +100,8 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) free_bootmem_cpumask_var(non_housekeeping_mask); return 0; } - free_bootmem_cpumask_var(tmp); } + free_bootmem_cpumask_var(tmp); if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) { if (IS_ENABLED(CONFIG_NO_HZ_FULL)) { -- 2.20.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f195.google.com ([209.85.215.195]:42406 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726230AbfDKDfW (ORCPT ); Wed, 10 Apr 2019 23:35:22 -0400 From: Nicholas Piggin Subject: [PATCH v2 4/5] kernel/sched/isolation: require a present CPU in housekeeping mask Date: Thu, 11 Apr 2019 13:34:47 +1000 Message-ID: <20190411033448.20842-5-npiggin@gmail.com> In-Reply-To: <20190411033448.20842-1-npiggin@gmail.com> References: <20190411033448.20842-1-npiggin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Thomas Gleixner , Frederic Weisbecker Cc: Nicholas Piggin , Ingo Molnar , Peter Zijlstra , "Rafael J . Wysocki" , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Message-ID: <20190411033447.i1azJiQhbZCRZ5D0Vm2aO-3RvIs57jDhTv3MAhFtNOI@z> During housekeeping mask setup, currently a possible CPU is required. That does not guarantee the CPU would be available at boot time, so check to ensure that at least one present CPU is in the mask. Signed-off-by: Nicholas Piggin --- kernel/sched/isolation.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index b02d148e7672..687302051a27 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -65,6 +65,7 @@ void __init housekeeping_init(void) static int __init housekeeping_setup(char *str, enum hk_flags flags) { cpumask_var_t non_housekeeping_mask; + cpumask_var_t tmp; int err; alloc_bootmem_cpumask_var(&non_housekeeping_mask); @@ -75,16 +76,23 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) return 0; } + alloc_bootmem_cpumask_var(&tmp); if (!housekeeping_flags) { alloc_bootmem_cpumask_var(&housekeeping_mask); cpumask_andnot(housekeeping_mask, cpu_possible_mask, non_housekeeping_mask); - if (cpumask_empty(housekeeping_mask)) + + cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask); + if (cpumask_empty(tmp)) { + pr_warn("Housekeeping: must include one present CPU, " + "using boot CPU:%d\n", smp_processor_id()); __cpumask_set_cpu(smp_processor_id(), housekeeping_mask); + __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask); + } } else { - cpumask_var_t tmp; - - alloc_bootmem_cpumask_var(&tmp); + cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask); + if (cpumask_empty(tmp)) + __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask); cpumask_andnot(tmp, cpu_possible_mask, non_housekeeping_mask); if (!cpumask_equal(tmp, housekeeping_mask)) { pr_warn("Housekeeping: nohz_full= must match isolcpus=\n"); @@ -92,8 +100,8 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) free_bootmem_cpumask_var(non_housekeeping_mask); return 0; } - free_bootmem_cpumask_var(tmp); } + free_bootmem_cpumask_var(tmp); if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) { if (IS_ENABLED(CONFIG_NO_HZ_FULL)) { -- 2.20.1