[PATCH] lib/flex_proportions.c: Remove local_irq_ops in fprop_new_period()

From: wuchi
Date: Sat Jun 04 2022 - 09:15:12 EST


The commit <e78d4833c03e28> (lib: Fix possible deadlock in flexible
proportion code) adds the local_irq_ops because percpu_counter_{sum
|add} ops'lock can cause deadlock by interrupts. Now percpu_counter
_{sum|add} ops use raw_spin_(un)lock_irq*, so revert the commit and
resolve the conflict.

Signed-off-by: wuchi <wuchi.zero@xxxxxxxxx>
---
lib/flex_proportions.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/lib/flex_proportions.c b/lib/flex_proportions.c
index 53e7eb1dd76c..05cccbcf1661 100644
--- a/lib/flex_proportions.c
+++ b/lib/flex_proportions.c
@@ -63,18 +63,13 @@ void fprop_global_destroy(struct fprop_global *p)
*/
bool fprop_new_period(struct fprop_global *p, int periods)
{
- s64 events;
- unsigned long flags;
+ s64 events = percpu_counter_sum(&p->events);

- local_irq_save(flags);
- events = percpu_counter_sum(&p->events);
/*
* Don't do anything if there are no events.
*/
- if (events <= 1) {
- local_irq_restore(flags);
+ if (events <= 1)
return false;
- }
write_seqcount_begin(&p->sequence);
if (periods < 64)
events -= events >> periods;
@@ -82,7 +77,6 @@ bool fprop_new_period(struct fprop_global *p, int periods)
percpu_counter_add(&p->events, -events);
p->period += periods;
write_seqcount_end(&p->sequence);
- local_irq_restore(flags);

return true;
}
--
2.20.1