psi: Fix trigger being fired unexpectedly at initial

When a trigger being created, its win.start_value and win.start_time are
reset to zero. If group->total[PSI_POLL][t->state] has accumulated before,
this trigger will be fired unexpectedly in the next period, even if its
growth time does not reach its threshold.

So set the window of the new trigger to the current state value.

Signed-off-by: Hailong Liu <liuhailong@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Link: https://lore.kernel.org/r/1648789811-3788971-1-git-send-email-liuhailong@linux.alibaba.com

diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index a4fa3aa..5a49a8c 100644 (file)
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -1117,7 +1117,8 @@ struct psi_trigger *psi_trigger_create(struct psi_group *group,
        t->state = state;
        t->threshold = threshold_us * NSEC_PER_USEC;
        t->win.size = window_us * NSEC_PER_USEC;
-       window_reset(&t->win, 0, 0, 0);
+       window_reset(&t->win, sched_clock(),
+                       group->total[PSI_POLL][t->state], 0);
 
        t->event = 0;
        t->last_event_time = 0;