diff options
| -rw-r--r-- | kernel/sched/psi.c | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 77d53c03a76f..d71dbc2356ff 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -820,20 +820,15 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, u64 now = cpu_clock(cpu); if (next->pid) { - bool identical_state; - psi_flags_change(next, 0, TSK_ONCPU); /* - * When switching between tasks that have an identical - * 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. + * Set TSK_ONCPU on @next's cgroups. If @next shares any + * ancestors with @prev, those will already have @prev's + * TSK_ONCPU bit set, and we can stop the iteration there. */ - identical_state = prev->psi_flags == next->psi_flags; iter = NULL; while ((group = iterate_groups(next, &iter))) { - if (identical_state && - per_cpu_ptr(group->pcpu, cpu)->tasks[NR_ONCPU]) { + if (per_cpu_ptr(group->pcpu, cpu)->tasks[NR_ONCPU]) { common = group; break; } @@ -877,10 +872,12 @@ void psi_task_switch(struct task_struct *prev, struct task_struct *next, psi_group_change(group, cpu, clear, set, now, wake_clock); /* - * TSK_ONCPU is handled up to the common ancestor. If we're tasked - * with dequeuing too, finish that for the rest of the hierarchy. + * TSK_ONCPU is handled up to the common ancestor. If there are + * any other differences between the two tasks (e.g. prev goes + * to sleep, or only one task is memstall), finish propagating + * those differences all the way up to the root. */ - if (sleep) { + if ((prev->psi_flags ^ next->psi_flags) & ~TSK_ONCPU) { clear &= ~TSK_ONCPU; for (; group; group = iterate_groups(prev, &iter)) psi_group_change(group, cpu, clear, set, now, wake_clock); |