X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fvppinfra%2Fbihash_template.c;h=e13ceb7173ae0574bff06c8828313a2da66d5e43;hb=74449b8b68801e0938f528f19d69e75644cb2ee9;hp=2b40af31d6fb9e8b174d45af151274c1fb60726d;hpb=e7d212fe41de88863884dc24dff9e24e5f37b421;p=vpp.git diff --git a/src/vppinfra/bihash_template.c b/src/vppinfra/bihash_template.c index 2b40af31d6f..e13ceb7173a 100644 --- a/src/vppinfra/bihash_template.c +++ b/src/vppinfra/bihash_template.c @@ -15,32 +15,52 @@ /** @cond DOCUMENTATION_IS_IN_BIHASH_DOC_H */ +static inline void *BV (alloc_aligned) (BVT (clib_bihash) * h, uword nbytes) +{ + uword rv; + + /* Round to an even number of cache lines */ + nbytes += CLIB_CACHE_LINE_BYTES - 1; + nbytes &= ~(CLIB_CACHE_LINE_BYTES - 1); + + rv = h->alloc_arena_next; + h->alloc_arena_next += nbytes; + + if (rv >= (h->alloc_arena + h->alloc_arena_size)) + os_out_of_memory (); + + return (void *) rv; +} + + void BV (clib_bihash_init) (BVT (clib_bihash) * h, char *name, u32 nbuckets, uword memory_size) { - void *oldheap; - int i; + uword bucket_size; nbuckets = 1 << (max_log2 (nbuckets)); h->name = (u8 *) name; h->nbuckets = nbuckets; h->log2_nbuckets = max_log2 (nbuckets); - h->cache_hits = 0; - h->cache_misses = 0; - h->mheap = mheap_alloc (0 /* use VM */ , memory_size); + /* + * Make sure the requested size is rational. The max table + * size without playing the alignment card is 64 Gbytes. + * If someone starts complaining that's not enough, we can shift + * the offset by CLIB_LOG2_CACHE_LINE_BYTES... + */ + ASSERT (memory_size < (1ULL << BIHASH_BUCKET_OFFSET_BITS)); - oldheap = clib_mem_set_heap (h->mheap); - vec_validate_aligned (h->buckets, nbuckets - 1, CLIB_CACHE_LINE_BYTES); - h->writer_lock = clib_mem_alloc_aligned (CLIB_CACHE_LINE_BYTES, - CLIB_CACHE_LINE_BYTES); - h->writer_lock[0] = 0; + h->alloc_arena = (uword) clib_mem_vm_alloc (memory_size); + h->alloc_arena_next = h->alloc_arena; + h->alloc_arena_size = memory_size; - for (i = 0; i < nbuckets; i++) - BV (clib_bihash_reset_cache) (h->buckets + i); + bucket_size = nbuckets * sizeof (h->buckets[0]); + h->buckets = BV (alloc_aligned) (h, bucket_size); - clib_mem_set_heap (oldheap); + h->alloc_lock = BV (alloc_aligned) (h, CLIB_CACHE_LINE_BYTES); + h->alloc_lock[0] = 0; h->fmt_fn = NULL; } @@ -53,7 +73,9 @@ void BV (clib_bihash_set_kvp_format_fn) (BVT (clib_bihash) * h, void BV (clib_bihash_free) (BVT (clib_bihash) * h) { - mheap_free (h->mheap); + vec_free (h->working_copies); + vec_free (h->freelists); + clib_mem_vm_free ((void *) (h->alloc_arena), h->alloc_arena_size); memset (h, 0, sizeof (*h)); } @@ -62,17 +84,12 @@ BVT (clib_bihash_value) * BV (value_alloc) (BVT (clib_bihash) * h, u32 log2_pages) { BVT (clib_bihash_value) * rv = 0; - void *oldheap; - ASSERT (h->writer_lock[0]); + ASSERT (h->alloc_lock[0]); if (log2_pages >= vec_len (h->freelists) || h->freelists[log2_pages] == 0) { - oldheap = clib_mem_set_heap (h->mheap); - - vec_validate (h->freelists, log2_pages); - rv = clib_mem_alloc_aligned ((sizeof (*rv) * (1 << log2_pages)), - CLIB_CACHE_LINE_BYTES); - clib_mem_set_heap (oldheap); + vec_validate_init_empty (h->freelists, log2_pages, 0); + rv = BV (alloc_aligned) (h, (sizeof (*rv) * (1 << log2_pages))); goto initialize; } rv = h->freelists[log2_pages]; @@ -93,10 +110,13 @@ static void BV (value_free) (BVT (clib_bihash) * h, BVT (clib_bihash_value) * v, u32 log2_pages) { - ASSERT (h->writer_lock[0]); + ASSERT (h->alloc_lock[0]); ASSERT (vec_len (h->freelists) > log2_pages); + if (CLIB_DEBUG > 0) + memset (v, 0xFE, sizeof (*v) * (1 << log2_pages)); + v->next_free = h->freelists[log2_pages]; h->freelists[log2_pages] = v; } @@ -106,17 +126,16 @@ BV (make_working_copy) (BVT (clib_bihash) * h, BVT (clib_bihash_bucket) * b) { BVT (clib_bihash_value) * v; BVT (clib_bihash_bucket) working_bucket __attribute__ ((aligned (8))); - void *oldheap; BVT (clib_bihash_value) * working_copy; u32 thread_index = os_get_thread_index (); int log2_working_copy_length; + ASSERT (h->alloc_lock[0]); + if (thread_index >= vec_len (h->working_copies)) { - oldheap = clib_mem_set_heap (h->mheap); vec_validate (h->working_copies, thread_index); vec_validate_init_empty (h->working_copy_lengths, thread_index, ~0); - clib_mem_set_heap (oldheap); } /* @@ -128,26 +147,20 @@ BV (make_working_copy) (BVT (clib_bihash) * h, BVT (clib_bihash_bucket) * b) log2_working_copy_length = h->working_copy_lengths[thread_index]; h->saved_bucket.as_u64 = b->as_u64; - oldheap = clib_mem_set_heap (h->mheap); if (b->log2_pages > log2_working_copy_length) { - if (working_copy) - clib_mem_free (working_copy); - - working_copy = clib_mem_alloc_aligned - (sizeof (working_copy[0]) * (1 << b->log2_pages), - CLIB_CACHE_LINE_BYTES); + /* + * It's not worth the bookkeeping to free working copies + * if (working_copy) + * clib_mem_free (working_copy); + */ + working_copy = BV (alloc_aligned) + (h, sizeof (working_copy[0]) * (1 << b->log2_pages)); h->working_copy_lengths[thread_index] = b->log2_pages; h->working_copies[thread_index] = working_copy; } - clib_mem_set_heap (oldheap); - - /* Lock the bucket... */ - while (BV (clib_bihash_lock_bucket) (b) == 0) - ; - v = BV (clib_bihash_get_value) (h, b->offset); clib_memcpy (working_copy, v, sizeof (*v) * (1 << b->log2_pages)); @@ -168,6 +181,8 @@ BV (split_and_rehash) BVT (clib_bihash_value) * new_values, *new_v; int i, j, length_in_kvs; + ASSERT (h->alloc_lock[0]); + new_values = BV (value_alloc) (h, new_log2_pages); length_in_kvs = (1 << old_log2_pages) * BIHASH_KVP_PER_PAGE; @@ -215,6 +230,8 @@ BV (split_and_rehash_linear) BVT (clib_bihash_value) * new_values; int i, j, new_length, old_length; + ASSERT (h->alloc_lock[0]); + new_values = BV (value_alloc) (h, new_log2_pages); new_length = (1 << new_log2_pages) * BIHASH_KVP_PER_PAGE; old_length = (1 << old_log2_pages) * BIHASH_KVP_PER_PAGE; @@ -250,13 +267,13 @@ BV (split_and_rehash_linear) return new_values; } -int BV (clib_bihash_add_del) - (BVT (clib_bihash) * h, BVT (clib_bihash_kv) * add_v, int is_add) +static 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) { u32 bucket_index; BVT (clib_bihash_bucket) * b, tmp_b; BVT (clib_bihash_value) * v, *new_v, *save_new_v, *working_copy; - int rv = 0; int i, limit; u64 hash, new_hash; u32 new_log2_pages, old_log2_pages; @@ -271,43 +288,49 @@ int BV (clib_bihash_add_del) hash >>= h->log2_nbuckets; - tmp_b.linear_search = 0; - - while (__sync_lock_test_and_set (h->writer_lock, 1)) - ; + BV (clib_bihash_lock_bucket) (b); /* First elt in the bucket? */ - if (b->offset == 0) + if (BV (clib_bihash_bucket_is_empty) (b)) { if (is_add == 0) { - rv = -1; - goto unlock; + BV (clib_bihash_unlock_bucket) (b); + return (-1); } + BV (clib_bihash_alloc_lock) (h); v = BV (value_alloc) (h, 0); + BV (clib_bihash_alloc_unlock) (h); *v->kvp = *add_v; - tmp_b.as_u64 = 0; + 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 (); b->as_u64 = tmp_b.as_u64; - goto unlock; + BV (clib_bihash_unlock_bucket) (b); + return (0); } - /* Note: this leaves the cache disabled */ - BV (make_working_copy) (h, b); - - v = BV (clib_bihash_get_value) (h, h->saved_bucket.offset); - + /* WARNING: we're still looking at the live copy... */ 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; if (is_add) { + /* + * Because reader threads are looking at live data, + * we have to be extra careful. Readers do NOT hold the + * bucket lock. We need to be SLOWER than a search, past the + * point where readers CHECK the bucket lock. + */ + /* * For obvious (in hindsight) reasons, see if we're supposed to * replace an existing key, then look for an empty slot. @@ -316,52 +339,93 @@ int BV (clib_bihash_add_del) { if (!memcmp (&(v->kvp[i]), &add_v->key, sizeof (add_v->key))) { + CLIB_MEMORY_BARRIER (); /* Add a delay */ clib_memcpy (&(v->kvp[i]), add_v, sizeof (*add_v)); - CLIB_MEMORY_BARRIER (); - /* Restore the previous (k,v) pairs */ - b->as_u64 = h->saved_bucket.as_u64; - goto unlock; + BV (clib_bihash_unlock_bucket) (b); + return (0); } } + /* + * Look for an empty slot. If found, use it + */ for (i = 0; i < limit; i++) { if (BV (clib_bihash_is_free) (&(v->kvp[i]))) { - clib_memcpy (&(v->kvp[i]), add_v, sizeof (*add_v)); - CLIB_MEMORY_BARRIER (); - b->as_u64 = h->saved_bucket.as_u64; + /* + * Copy the value first, so that if a reader manages + * to match the new key, the value will be right... + */ + clib_memcpy (&(v->kvp[i].value), + &add_v->value, sizeof (add_v->value)); + CLIB_MEMORY_BARRIER (); /* Make sure the value has settled */ + clib_memcpy (&(v->kvp[i]), &add_v->key, sizeof (add_v->key)); b->refcnt++; - goto unlock; + BV (clib_bihash_unlock_bucket) (b); + return (0); + } + } + /* look for stale data to overwrite */ + if (is_stale_cb) + { + for (i = 0; i < limit; i++) + { + if (is_stale_cb (&(v->kvp[i]), arg)) + { + CLIB_MEMORY_BARRIER (); + clib_memcpy (&(v->kvp[i]), add_v, sizeof (*add_v)); + BV (clib_bihash_unlock_bucket) (b); + return (0); + } } } - /* no room at the inn... split case... */ + /* Out of space in this bucket, split the bucket... */ } - else + else /* delete case */ { for (i = 0; i < limit; i++) { + /* Found the key? Kill it... */ if (!memcmp (&(v->kvp[i]), &add_v->key, sizeof (add_v->key))) { memset (&(v->kvp[i]), 0xff, sizeof (*(add_v))); - CLIB_MEMORY_BARRIER (); - if (PREDICT_TRUE (h->saved_bucket.refcnt > 1)) + /* Is the bucket empty? */ + if (PREDICT_TRUE (b->refcnt > 1)) { - h->saved_bucket.refcnt -= 1; - b->as_u64 = h->saved_bucket.as_u64; - goto unlock; + b->refcnt--; + BV (clib_bihash_unlock_bucket) (b); + return (0); } - else + else /* yes, free it */ { - tmp_b.as_u64 = 0; - goto free_old_bucket; + /* 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; + + /* And free the backing storage */ + BV (clib_bihash_alloc_lock) (h); + /* Note: v currently points into the middle of the bucket */ + v = BV (clib_bihash_get_value) (h, tmp_b.offset); + BV (value_free) (h, v, tmp_b.log2_pages); + BV (clib_bihash_alloc_unlock) (h); + return (0); } } } - rv = -3; - b->as_u64 = h->saved_bucket.as_u64; - goto unlock; + /* Not found... */ + BV (clib_bihash_unlock_bucket) (b); + return (-3); } + /* Move readers to a (locked) temp copy of the bucket */ + BV (clib_bihash_alloc_lock) (h); + BV (make_working_copy) (h, b); + + v = BV (clib_bihash_get_value) (h, h->saved_bucket.offset); + old_log2_pages = h->saved_bucket.log2_pages; new_log2_pages = old_log2_pages + 1; mark_bucket_linear = 0; @@ -426,21 +490,24 @@ expand_ok: tmp_b.offset = BV (clib_bihash_get_offset) (h, save_new_v); tmp_b.linear_search = mark_bucket_linear; tmp_b.refcnt = h->saved_bucket.refcnt + 1; - -free_old_bucket: - + tmp_b.lock = 0; CLIB_MEMORY_BARRIER (); b->as_u64 = tmp_b.as_u64; - v = BV (clib_bihash_get_value) (h, h->saved_bucket.offset); + BV (clib_bihash_alloc_unlock) (h); + return (0); +} - BV (value_free) (h, v, h->saved_bucket.log2_pages); +int BV (clib_bihash_add_del) + (BVT (clib_bihash) * h, BVT (clib_bihash_kv) * add_v, int is_add) +{ + return BV (clib_bihash_add_del_inline) (h, add_v, is_add, 0, 0); +} -unlock: - BV (clib_bihash_reset_cache) (b); - BV (clib_bihash_unlock_bucket) (b); - CLIB_MEMORY_BARRIER (); - h->writer_lock[0] = 0; - return rv; +int BV (clib_bihash_add_or_overwrite_stale) + (BVT (clib_bihash) * h, BVT (clib_bihash_kv) * add_v, + int (*stale_callback) (BVT (clib_bihash_kv) *, void *), void *arg) +{ + return BV (clib_bihash_add_del_inline) (h, add_v, 1, stale_callback, arg); } int BV (clib_bihash_search) @@ -450,9 +517,6 @@ int BV (clib_bihash_search) u64 hash; u32 bucket_index; BVT (clib_bihash_value) * v; -#if BIHASH_KVP_CACHE_SIZE > 0 - BVT (clib_bihash_kv) * kvp; -#endif BVT (clib_bihash_bucket) * b; int i, limit; @@ -463,26 +527,15 @@ int BV (clib_bihash_search) bucket_index = hash & (h->nbuckets - 1); b = &h->buckets[bucket_index]; - if (b->offset == 0) + if (BV (clib_bihash_bucket_is_empty) (b)) return -1; -#if BIHASH_KVP_CACHE_SIZE > 0 - /* Check the cache, if currently enabled */ - if (PREDICT_TRUE ((b->cache_lru & (1 << 15)) == 0)) + if (PREDICT_FALSE (b->lock)) { - limit = BIHASH_KVP_CACHE_SIZE; - kvp = b->cache; - for (i = 0; i < limit; i++) - { - if (BV (clib_bihash_key_compare) (kvp[i].key, search_key->key)) - { - *valuep = kvp[i]; - h->cache_hits++; - return 0; - } - } + volatile BVT (clib_bihash_bucket) * bv = b; + while (bv->lock) + CLIB_PAUSE (); } -#endif hash >>= h->log2_nbuckets; @@ -497,53 +550,12 @@ int BV (clib_bihash_search) if (BV (clib_bihash_key_compare) (v->kvp[i].key, search_key->key)) { *valuep = v->kvp[i]; - -#if BIHASH_KVP_CACHE_SIZE > 0 - u8 cache_slot; - /* Shut off the cache */ - if (BV (clib_bihash_lock_bucket) (b)) - { - cache_slot = BV (clib_bihash_get_lru) (b); - b->cache[cache_slot] = v->kvp[i]; - BV (clib_bihash_update_lru) (b, cache_slot); - - /* Reenable the cache */ - BV (clib_bihash_unlock_bucket) (b); - h->cache_misses++; - } -#endif return 0; } } return -1; } -u8 *BV (format_bihash_lru) (u8 * s, va_list * args) -{ -#if BIHASH_KVP_SIZE > 0 - int i; - BVT (clib_bihash_bucket) * b = va_arg (*args, BVT (clib_bihash_bucket) *); - u16 cache_lru = b->cache_lru; - - s = format (s, "cache %s, order ", cache_lru & (1 << 15) ? "on" : "off"); - - for (i = 0; i < BIHASH_KVP_CACHE_SIZE; i++) - s = format (s, "[%d] ", ((cache_lru >> (3 * i)) & 7)); - - return (s); -#else - return format (s, "cache not configured"); -#endif -} - -void -BV (clib_bihash_update_lru_not_inline) (BVT (clib_bihash_bucket) * b, u8 slot) -{ -#if BIHASH_KVP_SIZE > 0 - BV (clib_bihash_update_lru) (b, slot); -#endif -} - u8 *BV (format_bihash) (u8 * s, va_list * args) { BVT (clib_bihash) * h = va_arg (*args, BVT (clib_bihash) *); @@ -554,13 +566,14 @@ u8 *BV (format_bihash) (u8 * s, va_list * args) u64 active_elements = 0; u64 active_buckets = 0; u64 linear_buckets = 0; + u64 used_bytes; s = format (s, "Hash table %s\n", h->name ? h->name : (u8 *) "(unnamed)"); for (i = 0; i < h->nbuckets; i++) { b = &h->buckets[i]; - if (b->offset == 0) + if (BV (clib_bihash_bucket_is_empty) (b)) { if (verbose > 1) s = format (s, "[%d]: empty\n", i); @@ -631,10 +644,13 @@ u8 *BV (format_bihash) (u8 * s, va_list * args) } s = format (s, " %lld linear search buckets\n", linear_buckets); - s = format (s, " %lld cache hits, %lld cache misses\n", - h->cache_hits, h->cache_misses); - if (h->mheap) - s = format (s, " mheap: %U", format_mheap, h->mheap, 0 /* verbose */ ); + used_bytes = h->alloc_arena_next - h->alloc_arena; + s = format (s, + " arena: base %llx, next %llx\n" + " used %lld b (%lld Mbytes) of %lld b (%lld Mbytes)\n", + h->alloc_arena, h->alloc_arena_next, + used_bytes, used_bytes >> 20, + h->alloc_arena_size, h->alloc_arena_size >> 20); return s; } @@ -649,7 +665,7 @@ void BV (clib_bihash_foreach_key_value_pair) for (i = 0; i < h->nbuckets; i++) { b = &h->buckets[i]; - if (b->offset == 0) + if (BV (clib_bihash_bucket_is_empty) (b)) continue; v = BV (clib_bihash_get_value) (h, b->offset); @@ -661,9 +677,16 @@ void BV (clib_bihash_foreach_key_value_pair) continue; (*fp) (&v->kvp[k], arg); + /* + * In case the callback deletes the last entry in the bucket... + */ + if (BV (clib_bihash_bucket_is_empty) (b)) + goto doublebreak; } v++; } + doublebreak: + ; } }