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authorHonnappa Nagarahalli <honnappa.nagarahalli@arm.com>2018-10-26 00:37:29 -0500
committerThomas Monjalon <thomas@monjalon.net>2018-10-26 12:43:52 +0200
commit40f8e9c28c4e432a0a1300008a25097042382654 (patch)
treefb69a8245561171a626e13c58f18ab6b3a00bc7f
parente0130788576fb85039f5c491b82575a0190f5d4b (diff)
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hash: separate multi-writer from r/w concurrency
RW concurrency is required with single writer and multiple reader usecase as well. Hence, multi-writer should not be enabled by default when RW concurrency is enabled. Fixes: f2e3001b53ec ("hash: support read/write concurrency") Cc: stable@dpdk.org Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> Reviewed-by: Gavin Hu <gavin.hu@arm.com> Reviewed-by: Yipeng Wang <yipeng1.wang@intel.com> Acked-by: Bruce Richardson <bruce.richardson@intel.com>
-rw-r--r--lib/librte_hash/rte_cuckoo_hash.c49
-rw-r--r--lib/librte_hash/rte_cuckoo_hash.h8
-rw-r--r--test/test/test_hash_readwrite.c6
3 files changed, 37 insertions, 26 deletions
diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c
index 9a48934..3539a10 100644
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -136,9 +136,10 @@ rte_hash_create(const struct rte_hash_parameters *params)
char ext_ring_name[RTE_RING_NAMESIZE];
unsigned num_key_slots;
unsigned i;
- unsigned int hw_trans_mem_support = 0, multi_writer_support = 0;
+ unsigned int hw_trans_mem_support = 0, use_local_cache = 0;
unsigned int ext_table_support = 0;
unsigned int readwrite_concur_support = 0;
+ unsigned int writer_takes_lock = 0;
rte_hash_function default_hash_func = (rte_hash_function)rte_jhash;
@@ -162,19 +163,21 @@ rte_hash_create(const struct rte_hash_parameters *params)
if (params->extra_flag & RTE_HASH_EXTRA_FLAGS_TRANS_MEM_SUPPORT)
hw_trans_mem_support = 1;
- if (params->extra_flag & RTE_HASH_EXTRA_FLAGS_MULTI_WRITER_ADD)
- multi_writer_support = 1;
+ if (params->extra_flag & RTE_HASH_EXTRA_FLAGS_MULTI_WRITER_ADD) {
+ use_local_cache = 1;
+ writer_takes_lock = 1;
+ }
if (params->extra_flag & RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY) {
readwrite_concur_support = 1;
- multi_writer_support = 1;
+ writer_takes_lock = 1;
}
if (params->extra_flag & RTE_HASH_EXTRA_FLAGS_EXT_TABLE)
ext_table_support = 1;
/* Store all keys and leave the first entry as a dummy entry for lookup_bulk */
- if (multi_writer_support)
+ if (use_local_cache)
/*
* Increase number of slots by total number of indices
* that can be stored in the lcore caches
@@ -322,7 +325,7 @@ rte_hash_create(const struct rte_hash_parameters *params)
h->cmp_jump_table_idx = KEY_OTHER_BYTES;
#endif
- if (multi_writer_support) {
+ if (use_local_cache) {
h->local_free_slots = rte_zmalloc_socket(NULL,
sizeof(struct lcore_cache) * RTE_MAX_LCORE,
RTE_CACHE_LINE_SIZE, params->socket_id);
@@ -352,9 +355,10 @@ rte_hash_create(const struct rte_hash_parameters *params)
h->key_store = k;
h->free_slots = r;
h->hw_trans_mem_support = hw_trans_mem_support;
- h->multi_writer_support = multi_writer_support;
+ h->use_local_cache = use_local_cache;
h->readwrite_concur_support = readwrite_concur_support;
h->ext_table_support = ext_table_support;
+ h->writer_takes_lock = writer_takes_lock;
#if defined(RTE_ARCH_X86)
if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE2))
@@ -363,10 +367,11 @@ rte_hash_create(const struct rte_hash_parameters *params)
#endif
h->sig_cmp_fn = RTE_HASH_COMPARE_SCALAR;
- /* Turn on multi-writer only with explicit flag from user and TM
- * support.
+ /* Writer threads need to take the lock when:
+ * 1) RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY is enabled OR
+ * 2) RTE_HASH_EXTRA_FLAGS_MULTI_WRITER_ADD is enabled
*/
- if (h->multi_writer_support) {
+ if (h->writer_takes_lock) {
h->readwrite_lock = rte_malloc(NULL, sizeof(rte_rwlock_t),
RTE_CACHE_LINE_SIZE);
if (h->readwrite_lock == NULL)
@@ -425,10 +430,10 @@ rte_hash_free(struct rte_hash *h)
rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
- if (h->multi_writer_support) {
+ if (h->use_local_cache)
rte_free(h->local_free_slots);
+ if (h->writer_takes_lock)
rte_free(h->readwrite_lock);
- }
rte_ring_free(h->free_slots);
rte_ring_free(h->free_ext_bkts);
rte_free(h->key_store);
@@ -454,7 +459,7 @@ rte_hash_count(const struct rte_hash *h)
if (h == NULL)
return -EINVAL;
- if (h->multi_writer_support) {
+ if (h->use_local_cache) {
tot_ring_cnt = h->entries + (RTE_MAX_LCORE - 1) *
(LCORE_CACHE_SIZE - 1);
for (i = 0; i < RTE_MAX_LCORE; i++)
@@ -473,9 +478,9 @@ rte_hash_count(const struct rte_hash *h)
static inline void
__hash_rw_writer_lock(const struct rte_hash *h)
{
- if (h->multi_writer_support && h->hw_trans_mem_support)
+ if (h->writer_takes_lock && h->hw_trans_mem_support)
rte_rwlock_write_lock_tm(h->readwrite_lock);
- else if (h->multi_writer_support)
+ else if (h->writer_takes_lock)
rte_rwlock_write_lock(h->readwrite_lock);
}
@@ -491,9 +496,9 @@ __hash_rw_reader_lock(const struct rte_hash *h)
static inline void
__hash_rw_writer_unlock(const struct rte_hash *h)
{
- if (h->multi_writer_support && h->hw_trans_mem_support)
+ if (h->writer_takes_lock && h->hw_trans_mem_support)
rte_rwlock_write_unlock_tm(h->readwrite_lock);
- else if (h->multi_writer_support)
+ else if (h->writer_takes_lock)
rte_rwlock_write_unlock(h->readwrite_lock);
}
@@ -532,7 +537,7 @@ rte_hash_reset(struct rte_hash *h)
}
/* Repopulate the free slots ring. Entry zero is reserved for key misses */
- if (h->multi_writer_support)
+ if (h->use_local_cache)
tot_ring_cnt = h->entries + (RTE_MAX_LCORE - 1) *
(LCORE_CACHE_SIZE - 1);
else
@@ -548,7 +553,7 @@ rte_hash_reset(struct rte_hash *h)
(void *)((uintptr_t) i));
}
- if (h->multi_writer_support) {
+ if (h->use_local_cache) {
/* Reset local caches per lcore */
for (i = 0; i < RTE_MAX_LCORE; i++)
h->local_free_slots[i].len = 0;
@@ -566,7 +571,7 @@ enqueue_slot_back(const struct rte_hash *h,
struct lcore_cache *cached_free_slots,
void *slot_id)
{
- if (h->multi_writer_support) {
+ if (h->use_local_cache) {
cached_free_slots->objs[cached_free_slots->len] = slot_id;
cached_free_slots->len++;
} else
@@ -848,7 +853,7 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key,
__hash_rw_writer_unlock(h);
/* Did not find a match, so get a new slot for storing the new key */
- if (h->multi_writer_support) {
+ if (h->use_local_cache) {
lcore_id = rte_lcore_id();
cached_free_slots = &h->local_free_slots[lcore_id];
/* Try to get a free slot from the local cache */
@@ -1117,7 +1122,7 @@ remove_entry(const struct rte_hash *h, struct rte_hash_bucket *bkt, unsigned i)
struct lcore_cache *cached_free_slots;
bkt->sig_current[i] = NULL_SIGNATURE;
- if (h->multi_writer_support) {
+ if (h->use_local_cache) {
lcore_id = rte_lcore_id();
cached_free_slots = &h->local_free_slots[lcore_id];
/* Cache full, need to free it. */
diff --git a/lib/librte_hash/rte_cuckoo_hash.h b/lib/librte_hash/rte_cuckoo_hash.h
index 7753cd8..8c522ac 100644
--- a/lib/librte_hash/rte_cuckoo_hash.h
+++ b/lib/librte_hash/rte_cuckoo_hash.h
@@ -161,11 +161,15 @@ struct rte_hash {
/**< Length of hash key. */
uint8_t hw_trans_mem_support;
/**< If hardware transactional memory is used. */
- uint8_t multi_writer_support;
- /**< If multi-writer support is enabled. */
+ uint8_t use_local_cache;
+ /**< If multi-writer support is enabled, use local cache
+ * to allocate key-store slots.
+ */
uint8_t readwrite_concur_support;
/**< If read-write concurrency support is enabled */
uint8_t ext_table_support; /**< Enable extendable bucket table */
+ uint8_t writer_takes_lock;
+ /**< Indicates if the writer threads need to take lock */
rte_hash_function hash_func; /**< Function used to calculate hash. */
uint32_t hash_func_init_val; /**< Init value used by hash_func. */
rte_hash_cmp_eq_t rte_hash_custom_cmp_eq;
diff --git a/test/test/test_hash_readwrite.c b/test/test/test_hash_readwrite.c
index 2a4f7b9..a8fadd0 100644
--- a/test/test/test_hash_readwrite.c
+++ b/test/test/test_hash_readwrite.c
@@ -122,10 +122,12 @@ init_params(int use_htm, int use_jhash)
if (use_htm)
hash_params.extra_flag =
RTE_HASH_EXTRA_FLAGS_TRANS_MEM_SUPPORT |
- RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY;
+ RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY |
+ RTE_HASH_EXTRA_FLAGS_MULTI_WRITER_ADD;
else
hash_params.extra_flag =
- RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY;
+ RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY |
+ RTE_HASH_EXTRA_FLAGS_MULTI_WRITER_ADD;
hash_params.name = "tests";