[PATCH 6.4 049/800] tick/rcu: Fix bogus ratelimit condition

Greg Kroah-Hartman
2023-07-16T19:55:09Z

From: Wen Yang <wenyang.linux@foxmail.com>

[ 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@foxmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/tencent_5AAA3EEAB42095C9B7740BE62FBF9A67E007@qq.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/time/tick-sched.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

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 */
--
2.39.2