diff options
| -rw-r--r-- | include/linux/psi.h | 1 | ||||
| -rw-r--r-- | kernel/sched/core.c | 1 | ||||
| -rw-r--r-- | kernel/sched/psi.c | 65 | ||||
| -rw-r--r-- | kernel/sched/stats.h | 9 |
4 files changed, 24 insertions, 52 deletions
diff --git a/include/linux/psi.h b/include/linux/psi.h index 7361023f3fdd..65eb1476ac70 100644 --- a/include/linux/psi.h +++ b/include/linux/psi.h @@ -20,7 +20,6 @@ void psi_task_change(struct task_struct *task, int clear, int set); void psi_task_switch(struct task_struct *prev, struct task_struct *next, bool sleep); -void psi_memstall_tick(struct task_struct *task, int cpu); void psi_memstall_enter(unsigned long *flags); void psi_memstall_leave(unsigned long *flags); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 361974efc243..d2629fd2af07 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4551,7 +4551,6 @@ void scheduler_tick(void) update_thermal_load_avg(rq_clock_thermal(rq), rq, thermal_pressure); curr->sched_class->task_tick(rq, curr, 0); calc_global_load_tick(rq); - psi_task_tick(rq); rq_unlock(rq, &rf); diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 2293c45d289d..0fe6ff6a6a15 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -644,8 +644,7 @@ static void poll_timer_fn(struct timer_list *t) wake_up_interruptible(&group->poll_wait); } -static void record_times(struct psi_group_cpu *groupc, int cpu, - bool memstall_tick) +static void record_times(struct psi_group_cpu *groupc, int cpu) { u32 delta; u64 now; @@ -664,23 +663,6 @@ static void record_times(struct psi_group_cpu *groupc, int cpu, groupc->times[PSI_MEM_SOME] += delta; if (groupc->state_mask & (1 << PSI_MEM_FULL)) groupc->times[PSI_MEM_FULL] += delta; - else if (memstall_tick) { - u32 sample; - /* - * Since we care about lost potential, a - * memstall is FULL when there are no other - * working tasks, but also when the CPU is - * actively reclaiming and nothing productive - * could run even if it were runnable. - * - * When the timer tick sees a reclaiming CPU, - * regardless of runnable tasks, sample a FULL - * tick (or less if it hasn't been a full tick - * since the last state change). - */ - sample = min(delta, (u32)jiffies_to_nsecs(1)); - groupc->times[PSI_MEM_FULL] += sample; - } } if (groupc->state_mask & (1 << PSI_CPU_SOME)) { @@ -714,7 +696,7 @@ static void psi_group_change(struct psi_group *group, int cpu, */ write_seqcount_begin(&groupc->seq); - record_times(groupc, cpu, false); + record_times(groupc, cpu); for (t = 0, m = clear; m; m &= ~(1 << t), t++) { if (!(m & (1 << t))) @@ -738,6 +720,18 @@ static void psi_group_change(struct psi_group *group, int cpu, if (test_state(groupc->tasks, s)) state_mask |= (1 << s); } + + /* + * Since we care about lost potential, a memstall is FULL + * when there are no other working tasks, but also when + * the CPU is actively reclaiming and nothing productive + * could run even if it were runnable. So when the current + * task in a cgroup is in_memstall, the corresponding groupc + * on that cpu is in PSI_MEM_FULL state. + */ + if (groupc->tasks[NR_ONCPU] && cpu_curr(cpu)->in_memstall) + state_mask |= (1 << PSI_MEM_FULL); + groupc->state_mask = state_mask; write_seqcount_end(&groupc->seq); @@ -823,17 +817,21 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, void *iter; if (next->pid) { + bool identical_state; + psi_flags_change(next, 0, TSK_ONCPU); /* - * When moving state between tasks, the group that - * contains them both does not change: we can stop - * updating the tree once we reach the first common - * ancestor. Iterate @next's ancestors until we - * encounter @prev's state. + * When switching between tasks that have an identical + * runtime state, the cgroup that contains both tasks + * runtime state, the cgroup that contains both tasks + * we reach the first common ancestor. Iterate @next's + * ancestors only until we encounter @prev's ONCPU. */ + identical_state = prev->psi_flags == next->psi_flags; iter = NULL; while ((group = iterate_groups(next, &iter))) { - if (per_cpu_ptr(group->pcpu, cpu)->tasks[NR_ONCPU]) { + if (identical_state && + per_cpu_ptr(group->pcpu, cpu)->tasks[NR_ONCPU]) { common = group; break; } @@ -859,21 +857,6 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, } } -void psi_memstall_tick(struct task_struct *task, int cpu) -{ - struct psi_group *group; - void *iter = NULL; - - while ((group = iterate_groups(task, &iter))) { - struct psi_group_cpu *groupc; - - groupc = per_cpu_ptr(group->pcpu, cpu); - write_seqcount_begin(&groupc->seq); - record_times(groupc, cpu, true); - write_seqcount_end(&groupc->seq); - } -} - /** * psi_memstall_enter - mark the beginning of a memory stall section * @flags: flags to handle nested sections diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h index 33d0daf83842..9e4e67a94731 100644 --- a/kernel/sched/stats.h +++ b/kernel/sched/stats.h @@ -144,14 +144,6 @@ static inline void psi_sched_switch(struct task_struct *prev, psi_task_switch(prev, next, sleep); } -static inline void psi_task_tick(struct rq *rq) -{ - if (static_branch_likely(&psi_disabled)) - return; - - if (unlikely(rq->curr->in_memstall)) - psi_memstall_tick(rq->curr, cpu_of(rq)); -} #else /* CONFIG_PSI */ static inline void psi_enqueue(struct task_struct *p, bool wakeup) {} static inline void psi_dequeue(struct task_struct *p, bool sleep) {} @@ -159,7 +151,6 @@ static inline void psi_ttwu_dequeue(struct task_struct *p) {} static inline void psi_sched_switch(struct task_struct *prev, struct task_struct *next, bool sleep) {} -static inline void psi_task_tick(struct rq *rq) {} #endif /* CONFIG_PSI */ #ifdef CONFIG_SCHED_INFO |