Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux

There's a Niagara 2 memcpy fix in this tree and I have
a Kconfig fix from Dave Jones which requires the sparc-next
changes which went upstream yesterday.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 4e6a61b15e86..29ca1c6da594 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -45,6 +45,7 @@
 #include <linux/mutex.h>
 #include <linux/export.h>
 #include <linux/hardirq.h>
+#include <linux/delay.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/rcu.h>
@@ -81,6 +82,9 @@ void __rcu_read_unlock(void)
         } else {
                 barrier();  /* critical section before exit code. */
                 t->rcu_read_lock_nesting = INT_MIN;
+#ifdef CONFIG_PROVE_RCU_DELAY
+                udelay(10); /* Make preemption more probable. */
+#endif /* #ifdef CONFIG_PROVE_RCU_DELAY */
                 barrier();  /* assign before ->rcu_read_unlock_special load */
                 if (unlikely(ACCESS_ONCE(t->rcu_read_unlock_special)))
                         rcu_read_unlock_special(t);