From: Hao Lee haolee.swjtu@gmail.com
[ Upstream commit e38f89af6a13e895805febd3a329a13ab7e66fa4 ]
When a pending event exists and growth is less than the threshold, the current logic is to skip this trigger without generating event. However, from e6df4ead85d9 ("psi: fix possible trigger missing in the window"), our purpose is to generate event as long as pending event exists and the rate meets the limit, no matter what growth is. This patch handles this case properly.
Fixes: e6df4ead85d9 ("psi: fix possible trigger missing in the window") Signed-off-by: Hao Lee haolee.swjtu@gmail.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Acked-by: Suren Baghdasaryan surenb@google.com Link: https://lore.kernel.org/r/20220919072356.GA29069@haolee.io Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/sched/psi.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index ee2ecc081422..7f40d87e8f50 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -539,10 +539,12 @@ static u64 update_triggers(struct psi_group *group, u64 now)
/* Calculate growth since last update */ growth = window_update(&t->win, now, total[t->state]); - if (growth < t->threshold) - continue; + if (!t->pending_event) { + if (growth < t->threshold) + continue;
- t->pending_event = true; + t->pending_event = true; + } } /* Limit event signaling to once per window */ if (now < t->last_event_time + t->win.size)