- patches.fixes/patch-2.6.11-rc1: 2.6.11-rc1.

[linux-flexiantxendom0-3.2.10.git] / include / linux / rcupdate.h

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 4f4bf72..85674c4 100644 (file)
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -65,7 +65,6 @@ 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?         */
-       seqcount_t lock;        /* For atomic reads of cur and next_pending.  */
 } ____cacheline_maxaligned_in_smp;
 
 /* Is batch a before batch b ? */
@@ -88,9 +87,7 @@ static inline int rcu_batch_after(long a, long b)
 struct rcu_data {
        /* 1) quiescent state handling : */
        long            quiescbatch;     /* Batch # for grace period */
-       long            qsctr;           /* User-mode/idle loop etc. */
-       long            last_qsctr;      /* value of qsctr at beginning */
-                                        /* of rcu grace period */
+       int             passed_quiesc;   /* User-mode/idle loop etc. */
        int             qs_pending;      /* core waits for quiesc state */
 
        /* 2) batch handling */
@@ -111,17 +108,20 @@ extern struct rcu_ctrlblk rcu_ctrlblk;
 extern struct rcu_ctrlblk rcu_bh_ctrlblk;
 
 /*
- * Increment the quiscent state counter.
+ * Increment the quiescent state counter.
+ * The counter is a bit degenerated: We do not need to know
+ * how many quiescent states passed, just if there was at least
+ * one since the start of the grace period. Thus just a flag.
  */
 static inline void rcu_qsctr_inc(int cpu)
 {
        struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
-       rdp->qsctr++;
+       rdp->passed_quiesc = 1;
 }
 static inline void rcu_bh_qsctr_inc(int cpu)
 {
        struct rcu_data *rdp = &per_cpu(rcu_bh_data, cpu);
-       rdp->qsctr++;
+       rdp->passed_quiesc = 1;
 }
 
 static inline int __rcu_pending(struct rcu_ctrlblk *rcp,