This is a note to let you know that I've just added the patch titled
tick/rcu: Fix bogus ratelimit condition
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tick-rcu-fix-bogus-ratelimit-condition.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3ffc888825b112e0db8f61a93c6629aaf13da7b1
Author: Wen Yang <wenyang.linux@xxxxxxxxxxx>
Date: Fri May 5 00:12:53 2023 +0800
tick/rcu: Fix bogus ratelimit condition
[ Upstream commit a7e282c77785c7eabf98836431b1f029481085ad ]
The ratelimit logic in report_idle_softirq() is broken because the
exit condition is always true:
static int ratelimit;
if (ratelimit < 10)
return false; ---> always returns here
ratelimit++; ---> no chance to run
Make it check for >= 10 instead.
Fixes: 0345691b24c0 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle")
Signed-off-by: Wen Yang <wenyang.linux@xxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/tencent_5AAA3EEAB42095C9B7740BE62FBF9A67E007@xxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 42c0be3080bde..4df14db4da490 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1041,7 +1041,7 @@ static bool report_idle_softirq(void)
return false;
}
- if (ratelimit < 10)
+ if (ratelimit >= 10)
return false;
/* On RT, softirqs handling may be waiting on some lock */
