The patch titled
Subject: lib/flex_proportions.c: remove local_irq_ops in fprop_new_period()
has been added to the -mm mm-nonmm-unstable branch. Its filename is
lib-flex_proportionsc-remove-local_irq_ops-in-fprop_new_period.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-flex_proportionsc-remove-local_irq_ops-in-fprop_new_period.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: wuchi <wuchi.zero@xxxxxxxxx>
Subject: lib/flex_proportions.c: remove local_irq_ops in fprop_new_period()
Date: Sat, 4 Jun 2022 21:15:02 +0800
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@xxxxxxxxx
Signed-off-by: wuchi <wuchi.zero@xxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/flex_proportions.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
--- a/lib/flex_proportions.c~lib-flex_proportionsc-remove-local_irq_ops-in-fprop_new_period
+++ a/lib/flex_proportions.c
@@ -63,18 +63,13 @@ void fprop_global_destroy(struct fprop_g
*/
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_globa
percpu_counter_add(&p->events, -events);
p->period += periods;
write_seqcount_end(&p->sequence);
- local_irq_restore(flags);
return true;
}
_
Patches currently in -mm which might be from wuchi.zero@xxxxxxxxx are
lib-flex_proportionsc-remove-local_irq_ops-in-fprop_new_period.patch
