rcu: Correctly handle non-empty Tiny RCU callback list with none ready

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

diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index da775c8..bc84596 100644 (file)
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -22,13 +22,12 @@
  * For detailed explanation of Read-Copy Update mechanism see -
  *             Documentation/RCU
  */
-#include <linux/moduleparam.h>
 #include <linux/completion.h>
 #include <linux/interrupt.h>
 #include <linux/notifier.h>
 #include <linux/rcupdate.h>
 #include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/mutex.h>
 #include <linux/sched.h>
 #include <linux/types.h>
@@ -161,6 +160,11 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp)
 
        /* Move the ready-to-invoke callbacks to a local list. */
        local_irq_save(flags);
+       if (rcp->donetail == &rcp->rcucblist) {
+               /* No callbacks ready, so just leave. */
+               local_irq_restore(flags);
+               return;
+       }
        RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, -1));
        list = rcp->rcucblist;
        rcp->rcucblist = *rcp->donetail;