From ed3b362d54f0038cafc985248350d301af7af686 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Mon, 7 Feb 2022 16:59:10 +0100 Subject: sched/isolation: Split housekeeping cpumask per isolation features To prepare for supporting each housekeeping feature toward cpuset, split the global housekeeping cpumask per HK_TYPE_* entry. This will later allow, for example, to runtime modify the cpulist passed through "isolcpus=", "nohz_full=" and "rcu_nocbs=" kernel boot parameters. 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/20220207155910.527133-9-frederic@kernel.org --- kernel/sched/isolation.c | 91 +++++++++++++++++++++++++++++++++--------------- 1 file changed, 62 insertions(+), 29 deletions(-) (limited to 'kernel/sched') diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 883eee9fae22..b4d10815c45a 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -23,12 +23,17 @@ enum hk_flags { DEFINE_STATIC_KEY_FALSE(housekeeping_overridden); EXPORT_SYMBOL_GPL(housekeeping_overridden); -static cpumask_var_t housekeeping_mask; -static unsigned int housekeeping_flags; + +struct housekeeping { + cpumask_var_t cpumasks[HK_TYPE_MAX]; + unsigned long flags; +}; + +static struct housekeeping housekeeping; bool housekeeping_enabled(enum hk_type type) { - return !!(housekeeping_flags & BIT(type)); + return !!(housekeeping.flags & BIT(type)); } EXPORT_SYMBOL_GPL(housekeeping_enabled); @@ -37,12 +42,12 @@ int housekeeping_any_cpu(enum hk_type type) int cpu; if (static_branch_unlikely(&housekeeping_overridden)) { - if (housekeeping_flags & BIT(type)) { - cpu = sched_numa_find_closest(housekeeping_mask, smp_processor_id()); + if (housekeeping.flags & BIT(type)) { + cpu = sched_numa_find_closest(housekeeping.cpumasks[type], smp_processor_id()); if (cpu < nr_cpu_ids) return cpu; - return cpumask_any_and(housekeeping_mask, cpu_online_mask); + return cpumask_any_and(housekeeping.cpumasks[type], cpu_online_mask); } } return smp_processor_id(); @@ -52,8 +57,8 @@ EXPORT_SYMBOL_GPL(housekeeping_any_cpu); const struct cpumask *housekeeping_cpumask(enum hk_type type) { if (static_branch_unlikely(&housekeeping_overridden)) - if (housekeeping_flags & BIT(type)) - return housekeeping_mask; + if (housekeeping.flags & BIT(type)) + return housekeeping.cpumasks[type]; return cpu_possible_mask; } EXPORT_SYMBOL_GPL(housekeeping_cpumask); @@ -61,40 +66,53 @@ EXPORT_SYMBOL_GPL(housekeeping_cpumask); void housekeeping_affine(struct task_struct *t, enum hk_type type) { if (static_branch_unlikely(&housekeeping_overridden)) - if (housekeeping_flags & BIT(type)) - set_cpus_allowed_ptr(t, housekeeping_mask); + if (housekeeping.flags & BIT(type)) + set_cpus_allowed_ptr(t, housekeeping.cpumasks[type]); } EXPORT_SYMBOL_GPL(housekeeping_affine); bool housekeeping_test_cpu(int cpu, enum hk_type type) { if (static_branch_unlikely(&housekeeping_overridden)) - if (housekeeping_flags & BIT(type)) - return cpumask_test_cpu(cpu, housekeeping_mask); + if (housekeeping.flags & BIT(type)) + return cpumask_test_cpu(cpu, housekeeping.cpumasks[type]); return true; } EXPORT_SYMBOL_GPL(housekeeping_test_cpu); void __init housekeeping_init(void) { - if (!housekeeping_flags) + enum hk_type type; + + if (!housekeeping.flags) return; static_branch_enable(&housekeeping_overridden); - if (housekeeping_flags & HK_FLAG_TICK) + if (housekeeping.flags & HK_FLAG_TICK) sched_tick_offload_init(); - /* We need at least one CPU to handle housekeeping work */ - WARN_ON_ONCE(cpumask_empty(housekeeping_mask)); + for_each_set_bit(type, &housekeeping.flags, HK_TYPE_MAX) { + /* We need at least one CPU to handle housekeeping work */ + WARN_ON_ONCE(cpumask_empty(housekeeping.cpumasks[type])); + } +} + +static void __init housekeeping_setup_type(enum hk_type type, + cpumask_var_t housekeeping_staging) +{ + + alloc_bootmem_cpumask_var(&housekeeping.cpumasks[type]); + cpumask_copy(housekeeping.cpumasks[type], + housekeeping_staging); } -static int __init housekeeping_setup(char *str, enum hk_flags flags) +static int __init housekeeping_setup(char *str, unsigned long flags) { cpumask_var_t non_housekeeping_mask, housekeeping_staging; int err = 0; - if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) { + if ((flags & HK_FLAG_TICK) && !(housekeeping.flags & HK_FLAG_TICK)) { if (!IS_ENABLED(CONFIG_NO_HZ_FULL)) { pr_warn("Housekeeping: nohz unsupported." " Build with CONFIG_NO_HZ_FULL\n"); @@ -115,26 +133,41 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) 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) { + if (!housekeeping.flags) { pr_warn("Housekeeping: must include one present CPU, " "using boot CPU:%d\n", smp_processor_id()); } } - if (!housekeeping_flags) { - alloc_bootmem_cpumask_var(&housekeeping_mask); - cpumask_copy(housekeeping_mask, housekeeping_staging); + if (!housekeeping.flags) { + /* First setup call ("nohz_full=" or "isolcpus=") */ + enum hk_type type; + + for_each_set_bit(type, &flags, HK_TYPE_MAX) + housekeeping_setup_type(type, housekeeping_staging); } else { - if (!cpumask_equal(housekeeping_staging, housekeeping_mask)) { - pr_warn("Housekeeping: nohz_full= must match isolcpus=\n"); - goto free_housekeeping_staging; + /* Second setup call ("nohz_full=" after "isolcpus=" or the reverse) */ + enum hk_type type; + unsigned long iter_flags = flags & housekeeping.flags; + + for_each_set_bit(type, &iter_flags, HK_TYPE_MAX) { + if (!cpumask_equal(housekeeping_staging, + housekeeping.cpumasks[type])) { + pr_warn("Housekeeping: nohz_full= must match isolcpus=\n"); + goto free_housekeeping_staging; + } } + + iter_flags = flags & ~housekeeping.flags; + + for_each_set_bit(type, &iter_flags, HK_TYPE_MAX) + housekeeping_setup_type(type, housekeeping_staging); } - if ((flags & HK_FLAG_TICK) && !(housekeeping_flags & HK_FLAG_TICK)) + if ((flags & HK_FLAG_TICK) && !(housekeeping.flags & HK_FLAG_TICK)) tick_nohz_full_setup(non_housekeeping_mask); - housekeeping_flags |= flags; + housekeeping.flags |= flags; err = 1; free_housekeeping_staging: @@ -147,7 +180,7 @@ free_non_housekeeping_mask: static int __init housekeeping_nohz_full_setup(char *str) { - unsigned int flags; + unsigned long flags; flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC | HK_FLAG_KTHREAD; @@ -158,7 +191,7 @@ __setup("nohz_full=", housekeeping_nohz_full_setup); static int __init housekeeping_isolcpus_setup(char *str) { - unsigned int flags = 0; + unsigned long flags = 0; bool illegal = false; char *par; int len; -- cgit v1.2.3