From 6367b600e31c6b211eadee7bf7f4ed8c755e9176 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 7 Feb 2022 16:59:07 +0100 Subject: [PATCH] sched/isolation: Consolidate check for housekeeping minimum service There can be two subsequent calls to housekeeping_setup() due to "nohz_full=" and "isolcpus=" that can mix up. The two passes each have their own way to deal with an empty housekeeping set of CPUs. Consolidate this part and remove the awful "tmp" based naming. Signed-off-by: Frederic Weisbecker Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Juri Lelli Reviewed-by: Phil Auld Link: https://lore.kernel.org/r/20220207155910.527133-6-frederic@kernel.org --- kernel/sched/isolation.c | 35 +++++++++++++++++------------------ 1 file changed, 17 insertions(+), 18 deletions(-) diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index a735d9e229dde..23085e665faac 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -91,8 +91,7 @@ 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; + cpumask_var_t non_housekeeping_mask, housekeeping_staging; alloc_bootmem_cpumask_var(&non_housekeeping_mask); if (cpulist_parse(str, non_housekeeping_mask) < 0) { @@ -101,32 +100,32 @@ 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); + alloc_bootmem_cpumask_var(&housekeeping_staging); + cpumask_andnot(housekeeping_staging, + cpu_possible_mask, non_housekeeping_mask); - cpumask_andnot(tmp, cpu_present_mask, non_housekeeping_mask); - if (cpumask_empty(tmp)) { + if (!cpumask_intersects(cpu_present_mask, housekeeping_staging)) { + __cpumask_set_cpu(smp_processor_id(), housekeeping_staging); + __cpumask_clear_cpu(smp_processor_id(), non_housekeeping_mask); + if (!housekeeping_flags) { 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); } + } + + if (!housekeeping_flags) { + alloc_bootmem_cpumask_var(&housekeeping_mask); + cpumask_copy(housekeeping_mask, housekeeping_staging); } else { - 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)) { + if (!cpumask_equal(housekeeping_staging, housekeeping_mask)) { pr_warn("Housekeeping: nohz_full= must match isolcpus=\n"); - free_bootmem_cpumask_var(tmp); + free_bootmem_cpumask_var(housekeeping_staging); free_bootmem_cpumask_var(non_housekeeping_mask); return 0; } } - free_bootmem_cpumask_var(tmp); + + free_bootmem_cpumask_var(housekeeping_staging); if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) { if (IS_ENABLED(CONFIG_NO_HZ_FULL)) { -- 2.30.2