Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull two small RCU fixlets from Ingo Molnar.

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcu: Make rcu_nocb_poll an early_param instead of module_param
  rcu: Prevent soft-lockup complaints about no-CBs CPUs

2 files changed, 11 insertions, 4 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 363e348bff9b..6c723811c0a0 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2438,7 +2438,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                         real-time workloads.  It can also improve energy
                         efficiency for asymmetric multiprocessors.
 
-        rcu_nocbs_poll  [KNL,BOOT]
+        rcu_nocb_poll   [KNL,BOOT]
                         Rather than requiring that offloaded CPUs
                         (specified by rcu_nocbs= above) explicitly
                         awaken the corresponding "rcuoN" kthreads,
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index f6e5ec2932b4..c1cc7e17ff9d 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -40,8 +40,7 @@
 #ifdef CONFIG_RCU_NOCB_CPU
 static cpumask_var_t rcu_nocb_mask; /* CPUs to have callbacks offloaded. */
 static bool have_rcu_nocb_mask;     /* Was rcu_nocb_mask allocated? */
-static bool rcu_nocb_poll;          /* Offload kthread are to poll. */
-module_param(rcu_nocb_poll, bool, 0444);
+static bool __read_mostly rcu_nocb_poll;    /* Offload kthread are to poll. */
 static char __initdata nocb_buf[NR_CPUS * 5];
 #endif /* #ifdef CONFIG_RCU_NOCB_CPU */
 
@@ -2159,6 +2158,13 @@ static int __init rcu_nocb_setup(char *str)
 }
 __setup("rcu_nocbs=", rcu_nocb_setup);
 
+static int __init parse_rcu_nocb_poll(char *arg)
+{
+        rcu_nocb_poll = 1;
+        return 0;
+}
+early_param("rcu_nocb_poll", parse_rcu_nocb_poll);
+
 /* Is the specified CPU a no-CPUs CPU? */
 static bool is_nocb_cpu(int cpu)
 {
@@ -2366,10 +2372,11 @@ static int rcu_nocb_kthread(void *arg)
         for (;;) {
                 /* If not polling, wait for next batch of callbacks. */
                 if (!rcu_nocb_poll)
-                        wait_event(rdp->nocb_wq, rdp->nocb_head);
+                        wait_event_interruptible(rdp->nocb_wq, rdp->nocb_head);
                 list = ACCESS_ONCE(rdp->nocb_head);
                 if (!list) {
                         schedule_timeout_interruptible(1);
+                        flush_signals(current);
                         continue;
                 }