diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2025-11-19 18:27:01 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2025-11-25 19:45:40 +0100 |
| commit | 35a5c37cb9f1f947dff18e7cfc75a8cfcfd557ca (patch) | |
| tree | 433d9305c706e6a9f64ba61ca6e57cdba42a433f /include | |
| parent | 79c11fb3da8581a2f222b290ce62a153ab1108fc (diff) | |
cpumask: Cache num_possible_cpus()
Reevaluating num_possible_cpus() over and over does not make sense. That
becomes a constant after init as cpu_possible_mask is marked ro_after_init.
Cache the value during initialization and provide that for consumption.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20251119172549.578653738@linutronix.de
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cpumask.h | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index feba06eb0a42..66694ee8d86e 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -126,6 +126,7 @@ extern struct cpumask __cpu_dying_mask; #define cpu_dying_mask ((const struct cpumask *)&__cpu_dying_mask) extern atomic_t __num_online_cpus; +extern unsigned int __num_possible_cpus; extern cpumask_t cpus_booted_once_mask; @@ -1152,13 +1153,13 @@ void init_cpu_possible(const struct cpumask *src); #define __assign_cpu(cpu, mask, val) \ __assign_bit(cpumask_check(cpu), cpumask_bits(mask), (val)) -#define set_cpu_possible(cpu, possible) assign_cpu((cpu), &__cpu_possible_mask, (possible)) #define set_cpu_enabled(cpu, enabled) assign_cpu((cpu), &__cpu_enabled_mask, (enabled)) #define set_cpu_present(cpu, present) assign_cpu((cpu), &__cpu_present_mask, (present)) #define set_cpu_active(cpu, active) assign_cpu((cpu), &__cpu_active_mask, (active)) #define set_cpu_dying(cpu, dying) assign_cpu((cpu), &__cpu_dying_mask, (dying)) void set_cpu_online(unsigned int cpu, bool online); +void set_cpu_possible(unsigned int cpu, bool possible); /** * to_cpumask - convert a NR_CPUS bitmap to a struct cpumask * @@ -1211,7 +1212,12 @@ static __always_inline unsigned int num_online_cpus(void) { return raw_atomic_read(&__num_online_cpus); } -#define num_possible_cpus() cpumask_weight(cpu_possible_mask) + +static __always_inline unsigned int num_possible_cpus(void) +{ + return __num_possible_cpus; +} + #define num_enabled_cpus() cpumask_weight(cpu_enabled_mask) #define num_present_cpus() cpumask_weight(cpu_present_mask) #define num_active_cpus() cpumask_weight(cpu_active_mask) |