diff options
| -rw-r--r-- | arch/x86/kernel/cpu/resctrl/internal.h | 24 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/resctrl/monitor.c | 20 |
2 files changed, 37 insertions, 7 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index b7b9d9230bef..81f5de916db8 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -7,6 +7,7 @@ #include <linux/kernfs.h> #include <linux/fs_context.h> #include <linux/jump_label.h> +#include <linux/tick.h> #include <asm/resctrl.h> @@ -55,6 +56,29 @@ /* Max event bits supported */ #define MAX_EVT_CONFIG_BITS GENMASK(6, 0) +/** + * cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that + * aren't marked nohz_full + * @mask: The mask to pick a CPU from. + * + * Returns a CPU in @mask. If there are housekeeping CPUs that don't use + * nohz_full, these are preferred. + */ +static inline unsigned int cpumask_any_housekeeping(const struct cpumask *mask) +{ + unsigned int cpu, hk_cpu; + + cpu = cpumask_any(mask); + if (!tick_nohz_full_cpu(cpu)) + return cpu; + + hk_cpu = cpumask_nth_andnot(0, mask, tick_nohz_full_mask); + if (hk_cpu < nr_cpu_ids) + cpu = hk_cpu; + + return cpu; +} + struct rdt_fs_context { struct kernfs_fs_context kfc; bool enable_cdpl2; diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 101f1b112d17..38f85e53ca93 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -761,7 +761,6 @@ static void mbm_update(struct rdt_resource *r, struct rdt_domain *d, void cqm_handle_limbo(struct work_struct *work) { unsigned long delay = msecs_to_jiffies(CQM_LIMBOCHECK_INTERVAL); - int cpu = smp_processor_id(); struct rdt_domain *d; mutex_lock(&rdtgroup_mutex); @@ -770,8 +769,11 @@ void cqm_handle_limbo(struct work_struct *work) __check_limbo(d, false); - if (has_busy_rmid(d)) - schedule_delayed_work_on(cpu, &d->cqm_limbo, delay); + if (has_busy_rmid(d)) { + d->cqm_work_cpu = cpumask_any_housekeeping(&d->cpu_mask); + schedule_delayed_work_on(d->cqm_work_cpu, &d->cqm_limbo, + delay); + } mutex_unlock(&rdtgroup_mutex); } @@ -781,7 +783,7 @@ void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms) unsigned long delay = msecs_to_jiffies(delay_ms); int cpu; - cpu = cpumask_any(&dom->cpu_mask); + cpu = cpumask_any_housekeeping(&dom->cpu_mask); dom->cqm_work_cpu = cpu; schedule_delayed_work_on(cpu, &dom->cqm_limbo, delay); @@ -791,7 +793,6 @@ void mbm_handle_overflow(struct work_struct *work) { unsigned long delay = msecs_to_jiffies(MBM_OVERFLOW_INTERVAL); struct rdtgroup *prgrp, *crgrp; - int cpu = smp_processor_id(); struct list_head *head; struct rdt_resource *r; struct rdt_domain *d; @@ -815,7 +816,12 @@ void mbm_handle_overflow(struct work_struct *work) update_mba_bw(prgrp, d); } - schedule_delayed_work_on(cpu, &d->mbm_over, delay); + /* + * Re-check for housekeeping CPUs. This allows the overflow handler to + * move off a nohz_full CPU quickly. + */ + d->mbm_work_cpu = cpumask_any_housekeeping(&d->cpu_mask); + schedule_delayed_work_on(d->mbm_work_cpu, &d->mbm_over, delay); out_unlock: mutex_unlock(&rdtgroup_mutex); @@ -828,7 +834,7 @@ void mbm_setup_overflow_handler(struct rdt_domain *dom, unsigned long delay_ms) if (!static_branch_likely(&rdt_mon_enable_key)) return; - cpu = cpumask_any(&dom->cpu_mask); + cpu = cpumask_any_housekeeping(&dom->cpu_mask); dom->mbm_work_cpu = cpu; schedule_delayed_work_on(cpu, &dom->mbm_over, delay); } |