diff options
| author |   Yafang Shao <laoar.shao@gmail.com> | 2025-01-03 10:24:06 +0800 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2025-01-13 14:10:25 +0100 |
| commit | 8722903cbb8f0d51057fbf9ef1c680756b74119e (patch) | |
| tree | 7dabad538e408c65a8c4eae1f24d3b8dab138394 | |
| parent | sched/fair: Do not compute overloaded status unnecessarily during lb (diff) | |
| download | wireguard-linux-8722903cbb8f0d51057fbf9ef1c680756b74119e.tar.xz wireguard-linux-8722903cbb8f0d51057fbf9ef1c680756b74119e.zip | |
sched: Define sched_clock_irqtime as static key
Since CPU time accounting is a performance-critical path, let's define
sched_clock_irqtime as a static key to minimize potential overhead.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20250103022409.2544-2-laoar.shao@gmail.com
Diffstat (limited to '')
| -rw-r--r-- | kernel/sched/cputime.c | 16 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 13 |
2 files changed, 20 insertions, 9 deletions
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 0bed0fa1acd9..5d9143dd0879 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -9,6 +9,8 @@ #ifdef CONFIG_IRQ_TIME_ACCOUNTING +DEFINE_STATIC_KEY_FALSE(sched_clock_irqtime); + /* * There are no locks covering percpu hardirq/softirq time. * They are only modified in vtime_account, on corresponding CPU @@ -22,16 +24,14 @@ */ DEFINE_PER_CPU(struct irqtime, cpu_irqtime); -static int sched_clock_irqtime; - void enable_sched_clock_irqtime(void) { - sched_clock_irqtime = 1; + static_branch_enable(&sched_clock_irqtime); } void disable_sched_clock_irqtime(void) { - sched_clock_irqtime = 0; + static_branch_disable(&sched_clock_irqtime); } static void irqtime_account_delta(struct irqtime *irqtime, u64 delta, @@ -57,7 +57,7 @@ void irqtime_account_irq(struct task_struct *curr, unsigned int offset) s64 delta; int cpu; - if (!sched_clock_irqtime) + if (!irqtime_enabled()) return; cpu = smp_processor_id(); @@ -90,8 +90,6 @@ static u64 irqtime_tick_accounted(u64 maxtime) #else /* CONFIG_IRQ_TIME_ACCOUNTING */ -#define sched_clock_irqtime (0) - static u64 irqtime_tick_accounted(u64 dummy) { return 0; @@ -478,7 +476,7 @@ void account_process_tick(struct task_struct *p, int user_tick) if (vtime_accounting_enabled_this_cpu()) return; - if (sched_clock_irqtime) { + if (irqtime_enabled()) { irqtime_account_process_tick(p, user_tick, 1); return; } @@ -507,7 +505,7 @@ void account_idle_ticks(unsigned long ticks) { u64 cputime, steal; - if (sched_clock_irqtime) { + if (irqtime_enabled()) { irqtime_account_idle_ticks(ticks); return; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 300db6fe53eb..3da237c934e7 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -3233,6 +3233,12 @@ struct irqtime { }; DECLARE_PER_CPU(struct irqtime, cpu_irqtime); +DECLARE_STATIC_KEY_FALSE(sched_clock_irqtime); + +static inline int irqtime_enabled(void) +{ + return static_branch_likely(&sched_clock_irqtime); +} /* * Returns the irqtime minus the softirq time computed by ksoftirqd. @@ -3253,6 +3259,13 @@ static inline u64 irq_time_read(int cpu) return total; } +#else + +static inline int irqtime_enabled(void) +{ + return 0; +} + #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ #ifdef CONFIG_CPU_FREQ |