Merge branch 'next' of git://git.monstr.eu/linux-2.6-microblaze

[pandora-kernel.git] / kernel / srcu.c

diff --git a/kernel/srcu.c b/kernel/srcu.c
index c71e075..98d8c1e 100644 (file)
--- a/kernel/srcu.c
+++ b/kernel/srcu.c
@@ -31,6 +31,7 @@
 #include <linux/rcupdate.h>
 #include <linux/sched.h>
 #include <linux/smp.h>
+#include <linux/delay.h>
 #include <linux/srcu.h>
 
 static int init_srcu_struct_fields(struct srcu_struct *sp)
@@ -203,9 +204,14 @@ static void __synchronize_srcu(struct srcu_struct *sp, void (*sync_func)(void))
         * all srcu_read_lock() calls using the old counters have completed.
         * Their corresponding critical sections might well be still
         * executing, but the srcu_read_lock() primitives themselves
-        * will have finished executing.
+        * will have finished executing.  We initially give readers
+        * an arbitrarily chosen 10 microseconds to get out of their
+        * SRCU read-side critical sections, then loop waiting 1/HZ
+        * seconds per iteration.
         */
 
+       if (srcu_readers_active_idx(sp, idx))
+               udelay(CONFIG_SRCU_SYNCHRONIZE_DELAY);
        while (srcu_readers_active_idx(sp, idx))
                schedule_timeout_interruptible(1);