diff options
| author |   Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2022-08-25 18:41:30 +0200 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2022-09-19 14:35:08 +0200 |
| commit | 9458e0a78c45bc6537ce11eb9f03489eab92f9c2 (patch) | |
| tree | a8fb3afdf9cc749b56242fed822c372f8158432d /lib/flex_proportions.c | |
| parent | mm/compaction: Get rid of RT ifdeffery (diff) | |
| download | wireguard-linux-9458e0a78c45bc6537ce11eb9f03489eab92f9c2.tar.xz wireguard-linux-9458e0a78c45bc6537ce11eb9f03489eab92f9c2.zip | |
flex_proportions: Disable preemption entering the write section.
The seqcount fprop_global::sequence is not associated with a lock. The
write section (fprop_new_period()) is invoked from a timer and since the
softirq is preemptible on PREEMPT_RT it is possible to preempt the write
section which is not desited.
Disable preemption around the write section on PREEMPT_RT.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220825164131.402717-8-bigeasy@linutronix.de
Diffstat (limited to 'lib/flex_proportions.c')
| -rw-r--r-- | lib/flex_proportions.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/lib/flex_proportions.c b/lib/flex_proportions.c index 05cccbcf1661..83332fefa6f4 100644 --- a/lib/flex_proportions.c +++ b/lib/flex_proportions.c @@ -70,6 +70,7 @@ bool fprop_new_period(struct fprop_global *p, int periods) */ if (events <= 1) return false; + preempt_disable_nested(); write_seqcount_begin(&p->sequence); if (periods < 64) events -= events >> periods; @@ -77,6 +78,7 @@ bool fprop_new_period(struct fprop_global *p, int periods) percpu_counter_add(&p->events, -events); p->period += periods; write_seqcount_end(&p->sequence); + preempt_enable_nested(); return true; } |