X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=rculfhash.c;h=5ef2c781e3f6330ca631910df85f0a8ef92de954;hb=c1888f3a47cf8f7c213269888ce42d191de7e34a;hp=61dc09c3e2fe9408cd3edd3dde44e593e7d1966c;hpb=4c299dcbef9ad69c2dfbb9b4537b77252fc76d0d;p=urcu.git

diff --git a/rculfhash.c b/rculfhash.c
index 61dc09c..5ef2c78 100644
--- a/rculfhash.c
+++ b/rculfhash.c
@@ -242,15 +242,6 @@ struct partition_resize_work {
 		    unsigned long start, unsigned long len);
 };
 
-static
-void _cds_lfht_add(struct cds_lfht *ht,
-		cds_lfht_match_fct match,
-		const void *key,
-		unsigned long size,
-		struct cds_lfht_node *node,
-		struct cds_lfht_iter *unique_ret,
-		int bucket);
-
 /*
  * Algorithm to reverse bits in a word by lookup table, extended to
  * 64-bit words.
@@ -1158,6 +1149,11 @@ void remove_table(struct cds_lfht *ht, unsigned long i, unsigned long len)
 	partition_resize_helper(ht, i, len, remove_table_partition);
 }
 
+/*
+ * fini_table() is never called for first_order == 0, which is why
+ * free_by_rcu_order == 0 can be used as criterion to know if free must
+ * be called.
+ */
 static
 void fini_table(struct cds_lfht *ht,
 		unsigned long first_order, unsigned long last_order)
@@ -1275,6 +1271,36 @@ struct cds_lfht *_cds_lfht_new(unsigned long init_size,
 	if (!init_size || (init_size & (init_size - 1)))
 		return NULL;
 
+	/*
+	 * Memory management plugin default.
+	 */
+	if (!mm) {
+		if (!max_nr_buckets) {
+			/*
+			 * If the maximum number of buckets is not
+			 * specified, we cannot use the mmap allocator,
+			 * so fallback on order allocator.
+			 */
+			mm = &cds_lfht_mm_order;
+		} else if (CAA_BITS_PER_LONG > 32
+				&& max_nr_buckets <= (1ULL << 32)) {
+			/*
+			 * For 64-bit architectures, with max number of
+			 * buckets small enough not to use the entire
+			 * 64-bit memory mapping space (and allowing a
+			 * fair number of hash table instances), use the
+			 * mmap allocator, which is faster than the
+			 * order allocator.
+			 */
+			mm = &cds_lfht_mm_mmap;
+		} else {
+			/*
+			 * The fallback is to use the order allocator.
+			 */
+			mm = &cds_lfht_mm_order;
+		}
+	}
+
 	/* max_nr_buckets == 0 for order based mm means infinite */
 	if (mm == &cds_lfht_mm_order && !max_nr_buckets)
 		max_nr_buckets = 1UL << (MAX_TABLE_ORDER - 1);