ligang/vpp
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

bihash table size perf/scale improvements

Browse Source 
Directly allocate and carve cache-line-aligned chunks of virtual
memory. To a first approximation, bihash wasn't using
clib_mem_free(...).

We eliminate mheap object header/trailers, which improves space
efficiency. We also eliminate the 4gb bihash table size limit. An 8_8
bihash w/ 100 million random entries uses 3.8 Gbytes.

Change-Id: Icf925fdf99bce7d6ac407ac4edd30560b8f04808
Signed-off-by: Dave Barach <dave@barachs.net>
This commit is contained in:
Dave Barach
2018-02-22 09:48:45 -05:00
committed by Florin Coras
parent cae7134a8c
commit 97f5af0180
4 changed files with 84 additions and 44 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
src/vnet/fib/ip6_fib.c
View File

@ -600,12 +600,20 @@ ip6_fib_table_show_one (ip6_fib_t *fib,
u8 *
format_ip6_fib_table_memory (u8 * s, va_list * args)
{
uword bytes_inuse;
bytes_inuse =
ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash.alloc_arena_next
- ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash.alloc_arena;
bytes_inuse +=
ip6_main.ip6_table[IP6_FIB_TABLE_FWDING].ip6_hash.alloc_arena_next
- ip6_main.ip6_table[IP6_FIB_TABLE_FWDING].ip6_hash.alloc_arena;
s = format(s, "%=30s %=6d %=8ld\n",
"IPv6 unicast",
pool_elts(ip6_main.fibs),
mheap_bytes(ip6_main.ip6_table[IP6_FIB_TABLE_NON_FWDING].ip6_hash.mheap) +
mheap_bytes(ip6_main.ip6_table[IP6_FIB_TABLE_FWDING].ip6_hash.mheap));
bytes_inuse);
return (s);
}

76
src/vppinfra/bihash_template.c
View File

@ -15,10 +15,28 @@
/** @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;
uword bucket_size;
int i;
nbuckets = 1 << (max_log2 (nbuckets));
@ -29,19 +47,19 @@ void BV (clib_bihash_init)
h->cache_hits = 0;
h->cache_misses = 0;
h->mheap = mheap_alloc (0 /* use VM */ , memory_size);
h->alloc_arena = (uword) clib_mem_vm_alloc (memory_size);
h->alloc_arena_next = h->alloc_arena;
h->alloc_arena_size = memory_size;
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);
bucket_size = nbuckets * sizeof (h->buckets[0]);
h->buckets = BV (alloc_aligned) (h, bucket_size);
h->writer_lock = BV (alloc_aligned) (h, CLIB_CACHE_LINE_BYTES);
h->writer_lock[0] = 0;
for (i = 0; i < nbuckets; i++)
BV (clib_bihash_reset_cache) (h->buckets + i);
clib_mem_set_heap (oldheap);
h->fmt_fn = NULL;
}
@ -53,7 +71,9 @@ 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 +82,12 @@ 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]);
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];
@ -106,17 +121,14 @@ 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;
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);
}
/*
@ -128,22 +140,20 @@ 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)
;
@ -554,6 +564,7 @@ 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)");
@ -633,8 +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;
}

14
src/vppinfra/bihash_template.h
View File

@ -89,7 +89,14 @@ typedef struct
u64 cache_misses;
BVT (clib_bihash_value) ** freelists;
void *mheap;
/*
* Backing store allocation. Since bihash mananges its own
* freelists, we simple dole out memory at alloc_arena_next.
*/
uword alloc_arena;
uword alloc_arena_next;
uword alloc_arena_size;
/**
* A custom format function to print the Key and Value of bihash_key instead of default hexdump
@ -224,7 +231,7 @@ static inline void BV (clib_bihash_unlock_bucket)
static inline void *BV (clib_bihash_get_value) (BVT (clib_bihash) * h,
uword offset)
{
u8 *hp = h->mheap;
u8 *hp = (u8 *) h->alloc_arena;
u8 *vp = hp + offset;
return (void *) vp;
@ -235,10 +242,9 @@ static inline uword BV (clib_bihash_get_offset) (BVT (clib_bihash) * h,
{
u8 *hp, *vp;
hp = (u8 *) h->mheap;
hp = (u8 *) h->alloc_arena;
vp = (u8 *) v;
ASSERT ((vp - hp) < 0x100000000ULL);
return vp - hp;
}

24
src/vppinfra/test_bihash_template.c
View File

@ -36,6 +36,7 @@ typedef struct
int non_random_keys;
uword *key_hash;
u64 *keys;
uword hash_memory_size;
BVT (clib_bihash) hash;
clib_time_t clib_time;
@ -101,8 +102,7 @@ test_bihash (test_main_t * tm)
h = &tm->hash;
BV (clib_bihash_init) (h, "test", tm->nbuckets, 3ULL << 30);
BV (clib_bihash_init) (h, "test", tm->nbuckets, tm->hash_memory_size);
for (acycle = 0; acycle < tm->ncycles; acycle++)
{
@ -269,10 +269,11 @@ test_bihash (test_main_t * tm)
}
/* Clean up side-bet hash table and random key vector */
for (i = 0; i < tm->nitems; i++)
hash_unset (tm->key_hash, tm->keys[i]);
hash_free (tm->key_hash);
vec_reset_length (tm->keys);
/* Recreate hash table if we're going to need it again */
if (acycle != (tm->ncycles - 1))
tm->key_hash = hash_create (tm->nitems, sizeof (uword));
}
fformat (stdout, "End of run, should be empty...\n");
@ -322,6 +323,7 @@ test_bihash_main (test_main_t * tm)
int which = 0;
tm->report_every_n = 1;
tm->hash_memory_size = 4095ULL << 20;
while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
{
@ -344,6 +346,9 @@ test_bihash_main (test_main_t * tm)
;
else if (unformat (i, "report-every %d", &tm->report_every_n))
;
else if (unformat (i, "memory-size %U",
unformat_memory_size, &tm->hash_memory_size))
;
else if (unformat (i, "vec64"))
which = 1;
else if (unformat (i, "cache"))
@ -356,6 +361,12 @@ test_bihash_main (test_main_t * tm)
format_unformat_error, i);
}
/* Preallocate hash table, key vector */
tm->key_hash = hash_create (tm->nitems, sizeof (uword));
vec_validate (tm->keys, tm->nitems - 1);
_vec_len (tm->keys) = 0;
switch (which)
{
case 0:
@ -385,7 +396,7 @@ main (int argc, char *argv[])
clib_error_t *error;
test_main_t *tm = &test_main;
clib_mem_init (0, 3ULL << 30);
clib_mem_init (0, 4095ULL << 20);
tm->input = &i;
tm->seed = 0xdeaddabe;
@ -396,7 +407,6 @@ main (int argc, char *argv[])
tm->verbose = 1;
tm->search_iter = 1;
tm->careful_delete_tests = 0;
tm->key_hash = hash_create (0, sizeof (uword));
clib_time_init (&tm->clib_time);
unformat_init_command_line (&i, argv);