tick/rcu: Fix bogus ratelimit condition
authorWen Yang <wenyang.linux@foxmail.com>
Thu, 4 May 2023 16:12:53 +0000 (00:12 +0800)
committerThomas Gleixner <tglx@linutronix.de>
Sun, 18 Jun 2023 20:41:53 +0000 (22:41 +0200)
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
kernel/time/tick-sched.c

index 5225467..8905505 100644 (file)
@@ -1030,7 +1030,7 @@ 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 */