jrcu: Make the watchdog value a tuneable.
Also increase the default to 30 seconds.
Signed-off-by: Joe Korty <[email protected]>
Index: b/kernel/jrcu.c
===================================================================
--- a/kernel/jrcu.c
+++ b/kernel/jrcu.c
@@ -139,6 +139,8 @@ int rcu_scheduler_active __read_mostly;
int rcu_nmi_seen __read_mostly;
static u64 rcu_timestamp;
+int rcu_wdog = 30; /* rcu watchdog interval, in seconds */
+
/*
* Return our CPU id or zero if we are too early in the boot process to
* know what that is. For RCU to work correctly, a cpu named '0' must
@@ -327,7 +329,7 @@ static void __rcu_delimit_batches(struct
*/
rcu_now = sched_clock();
if (!eob && !rcu_timestamp
- && ((rcu_now - rcu_timestamp) > 3LL * NSEC_PER_SEC)) {
+ && ((rcu_now - rcu_timestamp) > (s64)rcu_wdog * NSEC_PER_SEC)) {
rcu_stats.nforced++;
WARN_ON_ONCE(1);
eob = 1;
@@ -576,6 +578,7 @@ static int rcu_debugfs_show(struct seq_f
raw_local_irq_enable();
seq_printf(m, "%14u: hz\n", rcu_hz);
+ seq_printf(m, "%14u: watchdog (secs)\n", rcu_wdog);
#ifdef CONFIG_JRCU_DAEMON
if (rcu_daemon)
seq_printf(m, "%14u: daemon priority\n", rcu_priority);
@@ -671,6 +674,12 @@ static ssize_t rcu_debugfs_write(struct
return -EINVAL;
rcu_hz = rcu_hz_wanted;
rcu_hz_period_us = USEC_PER_SEC / rcu_hz;
+ } else if (!strncmp(token, "wdog=", 5)) {
+ int wdog = -1;
+ sscanf(&token[5], "%d", &wdog);
+ if (wdog < 3 || wdog > 1000)
+ return -EINVAL;
+ rcu_wdog = wdog;
} else
return -EINVAL;