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[PATCH] psi: Fix trigger being fired unexpectedly at initial

Hailong Liu posted 1 patch 4 years, 2 months ago
There is a newer version of this series
kernel/sched/psi.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
[PATCH] psi: Fix trigger being fired unexpectedly at initial
Posted by Hailong Liu 4 years, 2 months ago 
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>
---
 kernel/sched/psi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index a4fa3aadfcba..5a49a8c8783e 100644
--- 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;
-- 
2.19.1.6.gb485710b
Re: [PATCH] psi: Fix trigger being fired unexpectedly at initial
Posted by Suren Baghdasaryan 4 years, 2 months ago 
On Thu, Mar 31, 2022 at 10:10 PM Hailong Liu
<liuhailong@linux.alibaba.com> wrote:
>
> 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.

Makes sense to me. Thanks!

>
> Signed-off-by: Hailong Liu <liuhailong@linux.alibaba.com>

Acked-by: Suren Baghdasaryan <surenb@google.com>

> ---
>  kernel/sched/psi.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
> index a4fa3aadfcba..5a49a8c8783e 100644
> --- 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;
> --
> 2.19.1.6.gb485710b
>
Re: [PATCH] psi: Fix trigger being fired unexpectedly at initial
Posted by Peter Zijlstra 4 years, 2 months ago 
On Fri, Apr 01, 2022 at 09:19:17AM -0700, Suren Baghdasaryan wrote:
> On Thu, Mar 31, 2022 at 10:10 PM Hailong Liu
> <liuhailong@linux.alibaba.com> wrote:
> >
> > 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.
> 
> Makes sense to me. Thanks!
> 
> >
> > Signed-off-by: Hailong Liu <liuhailong@linux.alibaba.com>
> 
> Acked-by: Suren Baghdasaryan <surenb@google.com>

Thanks!
[tip: sched/core] psi: Fix trigger being fired unexpectedly at initial
Posted by tip-bot2 for Hailong Liu 4 years, 1 month ago 
The following commit has been merged into the sched/core branch of tip:

Commit-ID:     915a087e4c47334a2f7ba2a4092c4bade0873769
Gitweb:        https://git.kernel.org/tip/915a087e4c47334a2f7ba2a4092c4bade0873769
Author:        Hailong Liu <liuhailong@linux.alibaba.com>
AuthorDate:    Fri, 01 Apr 2022 13:10:11 +08:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 22 Apr 2022 12:14:06 +02:00

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
---
 kernel/sched/psi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index a4fa3aa..5a49a8c 100644
--- 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;

Patchew 2.1-devel-ea86937

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