rculfhash: use hash for index if !HAVE_SCHED_GETCPU

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/rculfhash.c b/rculfhash.c
index e94b9b224422e8e316c5dbeea4be0aff0b002b36..46513dfd40562bb7c1e0bb24f39fee3656e378a2 100644 (file)
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -503,7 +503,7 @@ void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth);
  * In the unfortunate event the number of CPUs reported would be
  * inaccurate, we use modulo arithmetic on the number of CPUs we got.
  */
-#if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF)
+#if defined(HAVE_SYSCONF)
 
 static
 void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,
@@ -551,30 +551,36 @@ void free_split_items_count(struct ht_items_count *count)
        poison_free(count);
 }
 
+#if defined(HAVE_SCHED_GETCPU)
 static
-int ht_get_split_count_index(void)
+int ht_get_split_count_index(unsigned long hash)
 {
        int cpu;
 
        assert(split_count_mask >= 0);
        cpu = sched_getcpu();
        if (unlikely(cpu < 0))
-               return cpu;
+               return hash & split_count_mask;
        else
                return cpu & split_count_mask;
 }
+#else /* #if defined(HAVE_SCHED_GETCPU) */
+static
+int ht_get_split_count_index(unsigned long hash)
+{
+       return hash & split_count_mask;
+}
+#endif /* #else #if defined(HAVE_SCHED_GETCPU) */
 
 static
-void ht_count_add(struct cds_lfht *ht, unsigned long size)
+void ht_count_add(struct cds_lfht *ht, unsigned long size, unsigned long hash)
 {
        unsigned long split_count;
        int index;
 
        if (unlikely(!ht->split_count))
                return;
-       index = ht_get_split_count_index();
-       if (unlikely(index < 0))
-               return;
+       index = ht_get_split_count_index(hash);
        split_count = uatomic_add_return(&ht->split_count[index].add, 1);
        if (unlikely(!(split_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) {
                long count;
@@ -594,16 +600,14 @@ void ht_count_add(struct cds_lfht *ht, unsigned long size)
 }
 
 static
-void ht_count_del(struct cds_lfht *ht, unsigned long size)
+void ht_count_del(struct cds_lfht *ht, unsigned long size, unsigned long hash)
 {
        unsigned long split_count;
        int index;
 
        if (unlikely(!ht->split_count))
                return;
-       index = ht_get_split_count_index();
-       if (unlikely(index < 0))
-               return;
+       index = ht_get_split_count_index(hash);
        split_count = uatomic_add_return(&ht->split_count[index].del, 1);
        if (unlikely(!(split_count & ((1UL << COUNT_COMMIT_ORDER) - 1)))) {
                long count;
@@ -628,7 +632,7 @@ void ht_count_del(struct cds_lfht *ht, unsigned long size)
        }
 }
 
-#else /* #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */
+#else /* #if defined(HAVE_SYSCONF) */
 
 static const long nr_cpus_mask = -2;
 static const long split_count_mask = -2;
@@ -645,16 +649,16 @@ void free_split_items_count(struct ht_items_count *count)
 }
 
 static
-void ht_count_add(struct cds_lfht *ht, unsigned long size)
+void ht_count_add(struct cds_lfht *ht, unsigned long size, unsigned long hash)
 {
 }
 
 static
-void ht_count_del(struct cds_lfht *ht, unsigned long size)
+void ht_count_del(struct cds_lfht *ht, unsigned long size, unsigned long hash)
 {
 }
 
-#endif /* #else #if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF) */
+#endif /* #else #if defined(HAVE_SYSCONF) */
 
 
 static
@@ -1490,7 +1494,7 @@ void cds_lfht_add(struct cds_lfht *ht, struct cds_lfht_node *node)
 
        size = rcu_dereference(ht->t.size);
        _cds_lfht_add(ht, size, node, NULL, 0);
-       ht_count_add(ht, size);
+       ht_count_add(ht, size, hash);
 }
 
 struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht,
@@ -1505,7 +1509,7 @@ struct cds_lfht_node *cds_lfht_add_unique(struct cds_lfht *ht,
        size = rcu_dereference(ht->t.size);
        _cds_lfht_add(ht, size, node, &iter, 0);
        if (iter.node == node)
-               ht_count_add(ht, size);
+               ht_count_add(ht, size, hash);
        return iter.node;
 }
 
@@ -1522,7 +1526,7 @@ struct cds_lfht_node *cds_lfht_add_replace(struct cds_lfht *ht,
        for (;;) {
                _cds_lfht_add(ht, size, node, &iter, 0);
                if (iter.node == node) {
-                       ht_count_add(ht, size);
+                       ht_count_add(ht, size, hash);
                        return NULL;
                }
 
@@ -1543,13 +1547,15 @@ int cds_lfht_replace(struct cds_lfht *ht, struct cds_lfht_iter *old_iter,
 
 int cds_lfht_del(struct cds_lfht *ht, struct cds_lfht_iter *iter)
 {
-       unsigned long size;
+       unsigned long size, hash;
        int ret;
 
        size = rcu_dereference(ht->t.size);
        ret = _cds_lfht_del(ht, size, iter->node, 0);
-       if (!ret)
-               ht_count_del(ht, size);
+       if (!ret) {
+               hash = bit_reverse_ulong(iter->node->p.reverse_hash);
+               ht_count_del(ht, size, hash);
+       }
        return ret;
 }
 
@@ -1796,7 +1802,7 @@ void cds_lfht_resize_lazy(struct cds_lfht *ht, unsigned long size, int growth)
        }
 }
 
-#if defined(HAVE_SCHED_GETCPU) && defined(HAVE_SYSCONF)
+#if defined(HAVE_SYSCONF)
 
 static
 void cds_lfht_resize_lazy_count(struct cds_lfht *ht, unsigned long size,