From: Rik van Riel <[email protected]> Have the housekeeper CPU call account_process_tick to do tick based accounting for remote nohz_full CPUs.
Signed-off-by: Rik van Riel <[email protected]> --- kernel/time/timer.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 2ece3aa5069c..6adebb373317 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -42,6 +42,7 @@ #include <linux/sched/sysctl.h> #include <linux/slab.h> #include <linux/compat.h> +#include "../sched/sched.h" #include <asm/uaccess.h> #include <asm/unistd.h> @@ -1382,6 +1383,29 @@ unsigned long get_next_timer_interrupt(unsigned long now) } #endif +#ifdef CONFIG_NO_HZ_FULL +static void account_remote_process_ticks(void) +{ + int cpu; + + /* + * The current task on another CPU can get rescheduled while + * we are updating the statistics. The rcu read lock ensures + * the task does not get freed, so at worst the statistics will + * be off a little bit, which is expected with tick based sampling. + */ + rcu_read_lock(); + for_each_cpu_and(cpu, tick_nohz_full_mask, cpu_online_mask) { + struct task_struct *p = cpu_curr(cpu); + int user_tick = (per_cpu(context_tracking.state, cpu) == + CONTEXT_USER); + + account_process_tick(p, user_tick); + } + rcu_read_unlock(); +} +#endif + /* * Called from the timer interrupt handler to charge one tick to the current * process. user_tick is 1 if the tick is user time, 0 for system. @@ -1392,6 +1416,10 @@ void update_process_times(int user_tick) /* Note: this timer irq context must be accounted for as well. */ account_process_tick(p, user_tick); +#ifdef CONFIG_NO_HZ_FULL + if (is_timer_housekeeping_cpu(smp_processor_id())) + account_remote_process_ticks(); +#endif run_local_timers(); rcu_check_callbacks(user_tick); #ifdef CONFIG_IRQ_WORK -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
