vppinfra: improve bihash add/del performance
Measured improvement is from 439 to 167 clocks for add operation
in 16_8 case...
Type: improvement
Change-Id: I975ff46ff30b983a3ec80a5cde25ccb68d7fa03b
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vppinfra/bihash_template.c b/src/vppinfra/bihash_template.c
index 89bfc8b..7269959 100644
--- a/src/vppinfra/bihash_template.c
+++ b/src/vppinfra/bihash_template.c
@@ -106,7 +106,7 @@
sizeof (BVT (clib_bihash_kv))));
}
}
- CLIB_MEMORY_BARRIER ();
+ CLIB_MEMORY_STORE_BARRIER ();
h->instantiated = 1;
}
@@ -433,7 +433,7 @@
clib_memcpy_fast (working_copy, v, sizeof (*v) * (1 << b->log2_pages));
working_bucket.as_u64 = b->as_u64;
working_bucket.offset = BV (clib_bihash_get_offset) (h, working_copy);
- CLIB_MEMORY_BARRIER ();
+ CLIB_MEMORY_STORE_BARRIER ();
b->as_u64 = working_bucket.as_u64;
h->working_copies[thread_index] = working_copy;
}
@@ -534,14 +534,14 @@
return new_values;
}
-static inline int BV (clib_bihash_add_del_inline)
- (BVT (clib_bihash) * h, BVT (clib_bihash_kv) * add_v, int is_add,
+static_always_inline int BV (clib_bihash_add_del_inline_with_hash)
+ (BVT (clib_bihash) * h, BVT (clib_bihash_kv) * add_v, u64 hash, int is_add,
int (*is_stale_cb) (BVT (clib_bihash_kv) *, void *), void *arg)
{
BVT (clib_bihash_bucket) * b, tmp_b;
BVT (clib_bihash_value) * v, *new_v, *save_new_v, *working_copy;
int i, limit;
- u64 hash, new_hash;
+ u64 new_hash;
u32 new_log2_pages, old_log2_pages;
u32 thread_index = os_get_thread_index ();
int mark_bucket_linear;
@@ -562,8 +562,6 @@
BV (clib_bihash_alloc_unlock) (h);
}
- hash = BV (clib_bihash_hash) (add_v);
-
b = BV (clib_bihash_get_bucket) (h, hash);
hash >>= h->log2_nbuckets;
@@ -587,7 +585,7 @@
tmp_b.as_u64 = 0; /* clears bucket lock */
tmp_b.offset = BV (clib_bihash_get_offset) (h, v);
tmp_b.refcnt = 1;
- CLIB_MEMORY_BARRIER ();
+ CLIB_MEMORY_STORE_BARRIER ();
b->as_u64 = tmp_b.as_u64; /* unlocks the bucket */
BV (clib_bihash_increment_stat) (h, BIHASH_STAT_alloc_add, 1);
@@ -599,9 +597,10 @@
limit = BIHASH_KVP_PER_PAGE;
v = BV (clib_bihash_get_value) (h, b->offset);
- v += (b->linear_search == 0) ? hash & ((1 << b->log2_pages) - 1) : 0;
if (b->linear_search)
limit <<= b->log2_pages;
+ else
+ v += hash & ((1 << b->log2_pages) - 1);
if (is_add)
{
@@ -627,8 +626,8 @@
return (-2);
}
- CLIB_MEMORY_BARRIER (); /* Add a delay */
- clib_memcpy_fast (&(v->kvp[i]), add_v, sizeof (*add_v));
+ clib_memcpy_fast (&(v->kvp[i].value),
+ &add_v->value, sizeof (add_v->value));
BV (clib_bihash_unlock_bucket) (b);
BV (clib_bihash_increment_stat) (h, BIHASH_STAT_replace, 1);
return (0);
@@ -647,7 +646,7 @@
*/
clib_memcpy_fast (&(v->kvp[i].value),
&add_v->value, sizeof (add_v->value));
- CLIB_MEMORY_BARRIER (); /* Make sure the value has settled */
+ CLIB_MEMORY_STORE_BARRIER (); /* Make sure the value has settled */
clib_memcpy_fast (&(v->kvp[i]), &add_v->key,
sizeof (add_v->key));
b->refcnt++;
@@ -664,8 +663,8 @@
{
if (is_stale_cb (&(v->kvp[i]), arg))
{
- CLIB_MEMORY_BARRIER ();
clib_memcpy_fast (&(v->kvp[i]), add_v, sizeof (*add_v));
+ CLIB_MEMORY_STORE_BARRIER ();
BV (clib_bihash_unlock_bucket) (b);
BV (clib_bihash_increment_stat) (h, BIHASH_STAT_replace, 1);
return (0);
@@ -681,7 +680,7 @@
/* Found the key? Kill it... */
if (BV (clib_bihash_key_compare) (v->kvp[i].key, add_v->key))
{
- clib_memset (&(v->kvp[i]), 0xff, sizeof (*(add_v)));
+ clib_memset_u8 (&(v->kvp[i]), 0xff, sizeof (*(add_v)));
/* Is the bucket empty? */
if (PREDICT_TRUE (b->refcnt > 1))
{
@@ -696,14 +695,15 @@
b->linear_search = 0;
b->log2_pages = 0;
/* Clean up the bucket-level kvp array */
- clib_memset
- ((b + 1), 0xff,
- BIHASH_KVP_PER_PAGE * sizeof (BVT (clib_bihash_kv)));
+ clib_memset_u8 ((b + 1), 0xff, BIHASH_KVP_PER_PAGE *
+ sizeof (BVT (clib_bihash_kv)));
+ CLIB_MEMORY_STORE_BARRIER ();
BV (clib_bihash_unlock_bucket) (b);
BV (clib_bihash_increment_stat) (h, BIHASH_STAT_del, 1);
goto free_backing_store;
}
+ CLIB_MEMORY_STORE_BARRIER ();
BV (clib_bihash_unlock_bucket) (b);
BV (clib_bihash_increment_stat) (h, BIHASH_STAT_del, 1);
return (0);
@@ -712,7 +712,6 @@
{
/* Save old bucket value, need log2_pages to free it */
tmp_b.as_u64 = b->as_u64;
- CLIB_MEMORY_BARRIER ();
/* Kill and unlock the bucket */
b->as_u64 = 0;
@@ -818,7 +817,7 @@
tmp_b.refcnt = h->saved_bucket.refcnt + 1;
ASSERT (tmp_b.refcnt > 0);
tmp_b.lock = 0;
- CLIB_MEMORY_BARRIER ();
+ CLIB_MEMORY_STORE_BARRIER ();
b->as_u64 = tmp_b.as_u64;
#if BIHASH_KVP_AT_BUCKET_LEVEL
@@ -839,6 +838,15 @@
return (0);
}
+static_always_inline int BV (clib_bihash_add_del_inline)
+ (BVT (clib_bihash) * h, BVT (clib_bihash_kv) * add_v, int is_add,
+ int (*is_stale_cb) (BVT (clib_bihash_kv) *, void *), void *arg)
+{
+ u64 hash = BV (clib_bihash_hash) (add_v);
+ return BV (clib_bihash_add_del_inline_with_hash) (h, add_v, hash, is_add,
+ is_stale_cb, arg);
+}
+
int BV (clib_bihash_add_del)
(BVT (clib_bihash) * h, BVT (clib_bihash_kv) * add_v, int is_add)
{
diff --git a/src/vppinfra/bihash_template.h b/src/vppinfra/bihash_template.h
index 13a348f..b8e0a23 100644
--- a/src/vppinfra/bihash_template.h
+++ b/src/vppinfra/bihash_template.h
@@ -262,23 +262,25 @@
{
BVT (clib_bihash_bucket) unlocked_bucket, locked_bucket;
- do
- {
- locked_bucket.as_u64 = unlocked_bucket.as_u64 = b->as_u64;
- unlocked_bucket.lock = 0;
- locked_bucket.lock = 1;
- CLIB_PAUSE ();
- }
+ locked_bucket.as_u64 = unlocked_bucket.as_u64 = b->as_u64;
+ unlocked_bucket.lock = 0;
+ locked_bucket.lock = 1;
+
while (__atomic_compare_exchange_n (&b->as_u64, &unlocked_bucket.as_u64,
locked_bucket.as_u64, 1 /* weak */ ,
__ATOMIC_ACQUIRE,
- __ATOMIC_ACQUIRE) == 0);
+ __ATOMIC_ACQUIRE) == 0)
+ {
+ CLIB_PAUSE ();
+ locked_bucket.as_u64 = unlocked_bucket.as_u64 = b->as_u64;
+ unlocked_bucket.lock = 0;
+ locked_bucket.lock = 1;
+ }
}
static inline void BV (clib_bihash_unlock_bucket)
(BVT (clib_bihash_bucket) * b)
{
- CLIB_MEMORY_BARRIER ();
b->lock = 0;
}