[PATCH] pktcdvd: Don't waste kernel memory

[linux-2.6-omap-h63xx.git] / include / linux / rcupdate.h

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index a1d26cb28925dea07283800ff4a3888f79face2b..b87aefa082e2b69c868f673946dd1cbc16610a51 100644 (file)
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -65,6 +65,10 @@ struct rcu_ctrlblk {
        long    cur;            /* Current batch number.                      */
        long    completed;      /* Number of the last completed batch         */
        int     next_pending;   /* Is the next batch already waiting?         */
+
+       spinlock_t      lock    ____cacheline_internodealigned_in_smp;
+       cpumask_t       cpumask; /* CPUs that need to switch in order    */
+                                /* for current batch to proceed.        */
 } ____cacheline_internodealigned_in_smp;
 
 /* Is batch a before batch b ? */
@@ -236,11 +240,14 @@ extern int rcu_pending(int cpu);
  * This means that all preempt_disable code sequences, including NMI and
  * hardware-interrupt handlers, in progress on entry will have completed
  * before this primitive returns.  However, this does not guarantee that
- * softirq handlers will have completed, since in some kernels
+ * softirq handlers will have completed, since in some kernels, these
+ * handlers can run in process context, and can block.
  *
  * This primitive provides the guarantees made by the (deprecated)
  * synchronize_kernel() API.  In contrast, synchronize_rcu() only
  * guarantees that rcu_read_lock() sections will have completed.
+ * In "classic RCU", these two guarantees happen to be one and
+ * the same, but can differ in realtime RCU implementations.
  */
 #define synchronize_sched() synchronize_rcu()