From: Gavin Hu <gavin.hu@arm.com>
Date: Tue, 16 Jul 2019 19:23:56 +0000 (+0800)
Subject: hash: flush rings instead of dequeuing one by one
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=be0330cb1b4aed3869eea66bce6a36ca797c00b8;p=dpdk.git

hash: flush rings instead of dequeuing one by one

Within rte_hash_reset, calling a while loop to dequeue one by
one from the ring, while not using them at all, is wasting cycles,
The patch just flush the ring by resetting the indices can save CPU
cycles.

Signed-off-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Acked-by: Yipeng Wang <yipeng1.wang@intel.com>
---

diff --git a/lib/librte_hash/Makefile b/lib/librte_hash/Makefile
index c8c435dfde..5669d83f45 100644
--- a/lib/librte_hash/Makefile
+++ b/lib/librte_hash/Makefile
@@ -6,7 +6,7 @@ include $(RTE_SDK)/mk/rte.vars.mk
 # library name
 LIB = librte_hash.a
 
-CFLAGS += -O3
+CFLAGS += -O3 -DALLOW_EXPERIMENTAL_API
 CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)
 LDLIBS += -lrte_eal -lrte_ring
 
diff --git a/lib/librte_hash/meson.build b/lib/librte_hash/meson.build
index efc06ede5c..ebf70de890 100644
--- a/lib/librte_hash/meson.build
+++ b/lib/librte_hash/meson.build
@@ -14,3 +14,6 @@ headers = files('rte_cmp_arm64.h',
 
 sources = files('rte_cuckoo_hash.c', 'rte_fbk_hash.c')
 deps += ['ring']
+
+# rte ring reset is not yet part of stable API
+allow_experimental_apis = true
diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c
index d2509385b3..87a4c01f2f 100644
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -570,7 +570,6 @@ __hash_rw_reader_unlock(const struct rte_hash *h)
 void
 rte_hash_reset(struct rte_hash *h)
 {
-	void *ptr;
 	uint32_t tot_ring_cnt, i;
 
 	if (h == NULL)
@@ -581,16 +580,14 @@ rte_hash_reset(struct rte_hash *h)
 	memset(h->key_store, 0, h->key_entry_size * (h->entries + 1));
 	*h->tbl_chng_cnt = 0;
 
-	/* clear the free ring */
-	while (rte_ring_dequeue(h->free_slots, &ptr) == 0)
-		continue;
+	/* reset the free ring */
+	rte_ring_reset(h->free_slots);
 
-	/* clear free extendable bucket ring and memory */
+	/* flush free extendable bucket ring and memory */
 	if (h->ext_table_support) {
 		memset(h->buckets_ext, 0, h->num_buckets *
 						sizeof(struct rte_hash_bucket));
-		while (rte_ring_dequeue(h->free_ext_bkts, &ptr) == 0)
-			continue;
+		rte_ring_reset(h->free_ext_bkts);
 	}
 
 	/* Repopulate the free slots ring. Entry zero is reserved for key misses */