[PATCH tip/core/rcu 3/6] rcu: Stop disabling expedited RCU CPU stall warnings

From: Paul E. McKenney
Date: Mon Aug 22 2016 - 11:24:06 EST


Now that RCU expedited grace periods are always driven by a workqueue,
there is no need to account for signal reception, and thus no need
to disable expedited RCU CPU stall warnings due to signal reception.
This commit therefore removes the signal-reception checks, leaving a
WARN_ON() to catch possible future bugs.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree_exp.h | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 97f5ffe42b58..3a647eb96f23 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -427,12 +427,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
jiffies_stall);
if (ret > 0 || sync_rcu_preempt_exp_done(rnp_root))
return;
- if (ret < 0) {
- /* Hit a signal, disable CPU stall warnings. */
- swait_event(rsp->expedited_wq,
- sync_rcu_preempt_exp_done(rnp_root));
- return;
- }
+ WARN_ON(ret < 0); /* workqueues should not be signaled. */
pr_err("INFO: %s detected expedited stalls on CPUs/tasks: {",
rsp->name);
ndetected = 0;
--
2.5.2