From a91befde350375b1ff954635acdde14dc92cd9a8 Mon Sep 17 00:00:00 2001
From: wuchi <wuchi.zero@gmail.com>
Date: Sat, 4 Jun 2022 21:15:02 +0800
Subject: [PATCH] lib/flex_proportions.c: remove local_irq_ops in
fprop_new_period()
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.
Link: https://lkml.kernel.org/r/20220604131502.5190-1-wuchi.zero@gmail.com
Signed-off-by: wuchi <wuchi.zero@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
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;
}