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

[pandora-kernel.git] / kernel / rcu / tiny.c

diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c
index a501b4a..591af0c 100644 (file)
--- a/kernel/rcu/tiny.c
+++ b/kernel/rcu/tiny.c
@@ -137,6 +137,11 @@ 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, rcp->qlen, -1));
        list = rcp->rcucblist;
        rcp->rcucblist = *rcp->donetail;