rcu: Set RCU CPU stall times via sysfs

The default CONFIG_RCU_CPU_STALL_TIMEOUT value of 60 seconds has served
Linux users well for production use for quite some time.  However, for
debugging, there will be more than three minutes between subsequent
stall-warning messages.  This can be an annoyingly long wait if you
are trying to work out where the offending infinite loop is hiding.

Therefore, this commit provides a rcu_cpu_stall_timeout sysfs
parameter that may be adjusted at boot time and at runtime to speed
up debugging.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

1 files changed, 0 insertions, 6 deletions

diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 58c9fc3bc820..0328a537846a 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -314,12 +314,6 @@ struct rcu_data {
 #else
 #define RCU_STALL_DELAY_DELTA          0
 #endif
-
-#define RCU_SECONDS_TILL_STALL_CHECK   (CONFIG_RCU_CPU_STALL_TIMEOUT * HZ + \
-                                        RCU_STALL_DELAY_DELTA)
-                                                /* for rsp->jiffies_stall */
-#define RCU_SECONDS_TILL_STALL_RECHECK (3 * RCU_SECONDS_TILL_STALL_CHECK + 30)
-                                                /* for rsp->jiffies_stall */
 #define RCU_STALL_RAT_DELAY             2       /* Allow other CPUs time */
                                                 /*  to take at least one */
                                                 /*  scheduling clock irq */