[tip: sched/core] sched/psi: Delete the 'update_total' function parameter from update_triggers()

From: tip-bot2 for Yang Yang
Date: Wed Oct 11 2023 - 17:20:59 EST


The following commit has been merged into the sched/core branch of tip:

Commit-ID: 3657680f38cd7df413d665f2b2f38e9a78130d8b
Gitweb: https://git.kernel.org/tip/3657680f38cd7df413d665f2b2f38e9a78130d8b
Author: Yang Yang <yang.yang29@xxxxxxxxxx>
AuthorDate: Tue, 10 Oct 2023 16:45:43 +08:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Wed, 11 Oct 2023 23:08:09 +02:00

sched/psi: Delete the 'update_total' function parameter from update_triggers()

The 'update_total' parameter of update_triggers() is always true after the
previous commit:

80cc1d1d5ee3 ("sched/psi: Avoid updating PSI triggers and ->rtpoll_total when there are no state changes")

If the 'changed_states & group->rtpoll_states' condition is true,
'new_stall' in update_triggers() will be true, and then 'update_total'
should also be true.

So update_total is redundant - remove it.

[ mingo: Changelog updates ]

Signed-off-by: Yang Yang <yang.yang29@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Peter Ziljstra <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/202310101645437859599@xxxxxxxxxx
---
kernel/sched/psi.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 79f8db0..44a7877 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -434,14 +434,13 @@ static u64 window_update(struct psi_window *win, u64 now, u64 value)
return growth;
}

-static void update_triggers(struct psi_group *group, u64 now, bool *update_total,
+static void update_triggers(struct psi_group *group, u64 now,
enum psi_aggregators aggregator)
{
struct psi_trigger *t;
u64 *total = group->total[aggregator];
struct list_head *triggers;
u64 *aggregator_total;
- *update_total = false;

if (aggregator == PSI_AVGS) {
triggers = &group->avg_triggers;
@@ -471,14 +470,6 @@ static void update_triggers(struct psi_group *group, u64 now, bool *update_total
* events without dropping any).
*/
if (new_stall) {
- /*
- * Multiple triggers might be looking at the same state,
- * remember to update group->polling_total[] once we've
- * been through all of them. Also remember to extend the
- * polling time if we see new stall activity.
- */
- *update_total = true;
-
/* Calculate growth since last update */
growth = window_update(&t->win, now, total[t->state]);
if (!t->pending_event) {
@@ -563,7 +554,6 @@ static void psi_avgs_work(struct work_struct *work)
struct delayed_work *dwork;
struct psi_group *group;
u32 changed_states;
- bool update_total;
u64 now;

dwork = to_delayed_work(work);
@@ -582,7 +572,7 @@ static void psi_avgs_work(struct work_struct *work)
* go - see calc_avgs() and missed_periods.
*/
if (now >= group->avg_next_update) {
- update_triggers(group, now, &update_total, PSI_AVGS);
+ update_triggers(group, now, PSI_AVGS);
group->avg_next_update = update_averages(group, now);
}

@@ -638,7 +628,6 @@ static void psi_rtpoll_work(struct psi_group *group)
{
bool force_reschedule = false;
u32 changed_states;
- bool update_total;
u64 now;

mutex_lock(&group->rtpoll_trigger_lock);
@@ -705,7 +694,7 @@ static void psi_rtpoll_work(struct psi_group *group)

if (now >= group->rtpoll_next_update) {
if (changed_states & group->rtpoll_states) {
- update_triggers(group, now, &update_total, PSI_POLL);
+ update_triggers(group, now, PSI_POLL);
memcpy(group->rtpoll_total, group->total[PSI_POLL],
sizeof(group->rtpoll_total));
}