diff options
| -rw-r--r-- | include/linux/sched.h | 5 | ||||
| -rw-r--r-- | kernel/exit.c | 3 | ||||
| -rw-r--r-- | kernel/sched/core.c | 55 |
3 files changed, 59 insertions, 4 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 62bf15ff160d..ae6fddd190f0 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2533,6 +2533,11 @@ extern void wake_up_new_task(struct task_struct *tsk); #endif extern int sched_fork(unsigned long clone_flags, struct task_struct *p); extern void sched_dead(struct task_struct *p); +#if defined(CONFIG_SCHED_HMP) || defined(CONFIG_SCHED_FREQ_INPUT) +extern void sched_exit(struct task_struct *p); +#else +static inline void sched_exit(struct task_struct *p) { } +#endif extern void proc_caches_init(void); extern void flush_signals(struct task_struct *); diff --git a/kernel/exit.c b/kernel/exit.c index 07110c6020a0..18948169f997 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -699,6 +699,9 @@ void do_exit(long code) } exit_signals(tsk); /* sets PF_EXITING */ + + sched_exit(tsk); + /* * tsk->flags are checked in the futex code to protect against * an exiting task cleaning up the robust pi futexes. diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f3f5853a1822..014f7495a910 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1231,6 +1231,7 @@ static u64 sched_clock_at_init_jiffy; #define CURR_WINDOW_CONTRIB 1 #define PREV_WINDOW_CONTRIB 2 +#define DONT_ACCOUNT 4 /* Returns how undercommitted a CPU is given its current frequency and * task load (as measured in the previous window). Returns this value @@ -1275,7 +1276,7 @@ update_history(struct rq *rq, struct task_struct *p, u32 runtime, int samples, u64 sum = 0; if (new_window) { - p->ravg.flags = 0; + p->ravg.flags &= ~(CURR_WINDOW_CONTRIB | PREV_WINDOW_CONTRIB); if (runtime) p->ravg.flags |= PREV_WINDOW_CONTRIB; } @@ -1490,7 +1491,14 @@ static void update_task_ravg(struct task_struct *p, struct rq *rq, new_window = 1; } - if (update_sum) { + /* + * Tasks marked as DONT_ACCOUNT will not be accounted in + * rq->prev/curr_runnable_sum. We however want to perform + * maintenance duties on other counters such as window_start + * and roll over of curr_runnable_sum into prev_runnable_sum + * when update_task_ravg() is called on such tasks. + */ + if (update_sum && !(p->ravg.flags & DONT_ACCOUNT)) { delta = now - mark_start; delta = scale_exec_time(delta, rq); BUG_ON(delta < 0); @@ -1510,7 +1518,7 @@ static void update_task_ravg(struct task_struct *p, struct rq *rq, if (nr_full_windows) { window_start += nr_full_windows * window_size; - if (update_sum) + if (update_sum && !(p->ravg.flags & DONT_ACCOUNT)) sum = window_size; sum = scale_exec_time(sum, rq); update_history(rq, p, sum, nr_full_windows, @@ -1703,11 +1711,50 @@ static void reset_task_stats(struct task_struct *p) p->ravg.sum = 0; p->ravg.demand = 0; p->ravg.partial_demand = 0; - p->ravg.flags = 0; + p->ravg.flags &= ~(CURR_WINDOW_CONTRIB | PREV_WINDOW_CONTRIB); for (i = 0; i < RAVG_HIST_SIZE_MAX; ++i) p->ravg.sum_history[i] = 0; } +/* + * sched_exit() - Set DONT_ACCOUNT bit in task's ravg.flags + * + * This will remove an exiting task's stats from cpu busy counters + * (rq->curr/prev_runnable_sum) and also reset its stats. DONT_ACCOUNT bit is + * also set in exiting tasks ravg.flags so that its future usage of cpu is + * discounted from cpu busy time. + * + * We need this so that reset_all_windows_stats() can function correctly. + * reset_all_window_stats() depends on do_each_thread/for_each_thread task + * iterators to reset *all* task's statistics. Exiting tasks however become + * invisible to those iterators. sched_exit() is called on a exiting task prior + * to being removed from task_list, which will let reset_all_window_stats() + * function correctly. + */ +void sched_exit(struct task_struct *p) +{ + unsigned long flags; + int cpu = get_cpu(); + struct rq *rq = cpu_rq(cpu); + + raw_spin_lock_irqsave(&rq->lock, flags); + /* rq->curr == p */ + update_task_ravg(rq->curr, rq, TASK_UPDATE, sched_clock(), 0); + dequeue_task(rq, p, 0); + if (p->ravg.flags & CURR_WINDOW_CONTRIB) + rq->curr_runnable_sum -= p->ravg.partial_demand; + if (p->ravg.flags & PREV_WINDOW_CONTRIB) + rq->prev_runnable_sum -= p->ravg.demand; + BUG_ON((s64)rq->curr_runnable_sum < 0); + BUG_ON((s64)rq->prev_runnable_sum < 0); + reset_task_stats(p); + p->ravg.flags |= DONT_ACCOUNT; + enqueue_task(rq, p, 0); + raw_spin_unlock_irqrestore(&rq->lock, flags); + + put_cpu(); +} + /* Called with IRQs disabled */ void reset_all_window_stats(u64 window_start, unsigned int window_size) { |