From: Paul E. McKenney Date: Mon, 1 Oct 2018 22:42:44 +0000 (-0700) Subject: rcu: Parameterize rcu_check_gp_start_stall() X-Git-Tag: v5.0-rc1~152^2^2~17^4~10 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=791416c47153b45f640d52baaf30995d9d396a08;p=tomoyo%2Ftomoyo-test1.git rcu: Parameterize rcu_check_gp_start_stall() In order to debug forward-progress stalls, it is necessary to check for excessively delayed grace-period starts. This is currently done for RCU CPU stall warnings by rcu_check_gp_start_stall(), which checks to see if the start of a requested grace period has been delayed by an RCU CPU stall warning period. Because rcutorture will need to check for the time consumed by an RCU forward-progress delay, this commit promotes gpssdelay from a local variable to a formal parameter. It is not necessary to export rcu_check_gp_start_stall() because rcutorture will access it via a wrapper function. Signed-off-by: Paul E. McKenney --- diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 4933f5d9d992..36e30150e1e9 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2600,10 +2600,10 @@ static void force_quiescent_state(void) * This function checks for grace-period requests that fail to motivate * RCU to come out of its idle mode. */ -static void -rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp) +void +rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp, + const unsigned long gpssdelay) { - const unsigned long gpssdelay = rcu_jiffies_till_stall_check(); unsigned long flags; unsigned long j; struct rcu_node *rnp_root = rcu_get_root(); @@ -2690,7 +2690,7 @@ static __latent_entropy void rcu_process_callbacks(struct softirq_action *unused local_irq_restore(flags); } - rcu_check_gp_start_stall(rnp, rdp); + rcu_check_gp_start_stall(rnp, rdp, rcu_jiffies_till_stall_check()); /* If there are callbacks ready, invoke them. */ if (rcu_segcblist_ready_cbs(&rdp->cblist))