Minimize bihash memory consumption
Reference-count the number of entries in each bucket. If the reference
count goes to zero, free the backing store.
Add long-term churn-testing to test_bihash_template.c, thanks to
Andrew Yourtchenko for the initial implementation.
Change-Id: I4fbd9229cacfaba8027a85cbf87b74afdead6e39
Signed-off-by: Dave Barach <dave@barachs.net>
diff --git a/src/vppinfra/bihash_template.c b/src/vppinfra/bihash_template.c
index 3f25b02..2b40af3 100644
--- a/src/vppinfra/bihash_template.c
+++ b/src/vppinfra/bihash_template.c
@@ -290,6 +290,7 @@
*v->kvp = *add_v;
tmp_b.as_u64 = 0;
tmp_b.offset = BV (clib_bihash_get_offset) (h, v);
+ tmp_b.refcnt = 1;
b->as_u64 = tmp_b.as_u64;
goto unlock;
@@ -329,6 +330,7 @@
clib_memcpy (&(v->kvp[i]), add_v, sizeof (*add_v));
CLIB_MEMORY_BARRIER ();
b->as_u64 = h->saved_bucket.as_u64;
+ b->refcnt++;
goto unlock;
}
}
@@ -342,8 +344,17 @@
{
memset (&(v->kvp[i]), 0xff, sizeof (*(add_v)));
CLIB_MEMORY_BARRIER ();
- b->as_u64 = h->saved_bucket.as_u64;
- goto unlock;
+ if (PREDICT_TRUE (h->saved_bucket.refcnt > 1))
+ {
+ h->saved_bucket.refcnt -= 1;
+ b->as_u64 = h->saved_bucket.as_u64;
+ goto unlock;
+ }
+ else
+ {
+ tmp_b.as_u64 = 0;
+ goto free_old_bucket;
+ }
}
}
rv = -3;
@@ -411,18 +422,18 @@
goto try_resplit;
expand_ok:
- /* Keep track of the number of linear-scan buckets */
- if (tmp_b.linear_search ^ mark_bucket_linear)
- h->linear_buckets += (mark_bucket_linear == 1) ? 1 : -1;
-
tmp_b.log2_pages = new_log2_pages;
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:
CLIB_MEMORY_BARRIER ();
b->as_u64 = tmp_b.as_u64;
v = BV (clib_bihash_get_value) (h, h->saved_bucket.offset);
- BV (value_free) (h, v, old_log2_pages);
+
+ BV (value_free) (h, v, h->saved_bucket.log2_pages);
unlock:
BV (clib_bihash_reset_cache) (b);
@@ -541,6 +552,8 @@
BVT (clib_bihash_value) * v;
int i, j, k;
u64 active_elements = 0;
+ u64 active_buckets = 0;
+ u64 linear_buckets = 0;
s = format (s, "Hash table %s\n", h->name ? h->name : (u8 *) "(unnamed)");
@@ -554,6 +567,11 @@
continue;
}
+ active_buckets++;
+
+ if (b->linear_search)
+ linear_buckets++;
+
if (verbose)
{
s = format (s, "[%d]: heap offset %d, len %d, linear %d\n", i,
@@ -593,11 +611,30 @@
}
}
- s = format (s, " %lld active elements\n", active_elements);
+ s = format (s, " %lld active elements %lld active buckets\n",
+ active_elements, active_buckets);
s = format (s, " %d free lists\n", vec_len (h->freelists));
- s = format (s, " %d linear search buckets\n", h->linear_buckets);
+
+ for (i = 0; i < vec_len (h->freelists); i++)
+ {
+ u32 nfree = 0;
+ BVT (clib_bihash_value) * free_elt;
+
+ free_elt = h->freelists[i];
+ while (free_elt)
+ {
+ nfree++;
+ free_elt = free_elt->next_free;
+ }
+
+ s = format (s, " [len %d] %u free elts\n", 1 << i, nfree);
+ }
+
+ 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 */ );
return s;
}
diff --git a/src/vppinfra/bihash_template.h b/src/vppinfra/bihash_template.h
index 9df418b..4e5d995 100644
--- a/src/vppinfra/bihash_template.h
+++ b/src/vppinfra/bihash_template.h
@@ -61,11 +61,12 @@
u32 offset;
u8 linear_search;
u8 log2_pages;
- u16 cache_lru;
+ i16 refcnt;
};
u64 as_u64;
};
#if BIHASH_KVP_CACHE_SIZE > 0
+ u16 cache_lru;
BVT (clib_bihash_kv) cache[BIHASH_KVP_CACHE_SIZE];
#endif
} BVT (clib_bihash_bucket);
@@ -82,7 +83,6 @@
u32 nbuckets;
u32 log2_nbuckets;
- u32 linear_buckets;
u8 *name;
u64 cache_hits;
@@ -102,13 +102,11 @@
static inline void
BV (clib_bihash_update_lru) (BVT (clib_bihash_bucket) * b, u8 slot)
{
+#if BIHASH_KVP_CACHE_SIZE > 1
u16 value, tmp, mask;
u8 found_lru_pos;
u16 save_hi;
- if (BIHASH_KVP_CACHE_SIZE < 2)
- return;
-
ASSERT (slot < BIHASH_KVP_CACHE_SIZE);
/* First, find the slot in cache_lru */
@@ -154,6 +152,7 @@
value = save_hi | (tmp << 3) | slot;
b->cache_lru = value;
+#endif
}
void
@@ -197,28 +196,29 @@
static inline int BV (clib_bihash_lock_bucket) (BVT (clib_bihash_bucket) * b)
{
- BVT (clib_bihash_bucket) tmp_b;
- u64 rv;
+#if BIHASH_KVP_CACHE_SIZE > 0
+ u16 cache_lru_bit;
+ u16 rv;
- tmp_b.as_u64 = 0;
- tmp_b.cache_lru = 1 << 15;
+ cache_lru_bit = 1 << 15;
- rv = __sync_fetch_and_or (&b->as_u64, tmp_b.as_u64);
- tmp_b.as_u64 = rv;
+ rv = __sync_fetch_and_or (&b->cache_lru, cache_lru_bit);
/* Was already locked? */
- if (tmp_b.cache_lru & (1 << 15))
+ if (rv & (1 << 15))
return 0;
+#endif
return 1;
}
static inline void BV (clib_bihash_unlock_bucket)
(BVT (clib_bihash_bucket) * b)
{
- BVT (clib_bihash_bucket) tmp_b;
+#if BIHASH_KVP_CACHE_SIZE > 0
+ u16 cache_lru;
- tmp_b.as_u64 = b->as_u64;
- tmp_b.cache_lru &= ~(1 << 15);
- b->as_u64 = tmp_b.as_u64;
+ cache_lru = b->cache_lru & ~(1 << 15);
+ b->cache_lru = cache_lru;
+#endif
}
static inline void *BV (clib_bihash_get_value) (BVT (clib_bihash) * h,
diff --git a/src/vppinfra/test_bihash_template.c b/src/vppinfra/test_bihash_template.c
index 589c815..2d4b553 100644
--- a/src/vppinfra/test_bihash_template.c
+++ b/src/vppinfra/test_bihash_template.c
@@ -15,6 +15,8 @@
#include <vppinfra/time.h>
#include <vppinfra/cache.h>
#include <vppinfra/error.h>
+#include <sys/resource.h>
+#include <stdio.h>
#include <vppinfra/bihash_8_8.h>
#include <vppinfra/bihash_template.h>
@@ -26,6 +28,8 @@
u64 seed;
u32 nbuckets;
u32 nitems;
+ u32 ncycles;
+ u32 report_every_n;
u32 search_iter;
int careful_delete_tests;
int verbose;
@@ -93,144 +97,185 @@
f64 before, delta;
BVT (clib_bihash) * h;
BVT (clib_bihash_kv) kv;
+ u32 acycle;
h = &tm->hash;
BV (clib_bihash_init) (h, "test", tm->nbuckets, 3ULL << 30);
- fformat (stdout, "Pick %lld unique %s keys...\n",
- tm->nitems, tm->non_random_keys ? "non-random" : "random");
- for (i = 0; i < tm->nitems; i++)
+ for (acycle = 0; acycle < tm->ncycles; acycle++)
{
- u64 rndkey;
-
- if (tm->non_random_keys == 0)
+ if ((acycle % tm->report_every_n) == 0)
{
+ fformat (stdout, "Cycle %lld out of %lld...\n",
+ acycle, tm->ncycles);
- again:
- rndkey = random_u64 (&tm->seed);
-
- p = hash_get (tm->key_hash, rndkey);
- if (p)
- goto again;
+ fformat (stdout, "Pick %lld unique %s keys...\n",
+ tm->nitems, tm->non_random_keys ? "non-random" : "random");
}
- else
- rndkey = (u64) (i + 1) << 16;
- hash_set (tm->key_hash, rndkey, i + 1);
- vec_add1 (tm->keys, rndkey);
- }
-
- fformat (stdout, "Add items...\n");
- for (i = 0; i < tm->nitems; i++)
- {
- kv.key = tm->keys[i];
- kv.value = i + 1;
-
- BV (clib_bihash_add_del) (h, &kv, 1 /* is_add */ );
-
- if (tm->verbose > 1)
+ for (i = 0; i < tm->nitems; i++)
{
- fformat (stdout, "--------------------\n");
- fformat (stdout, "After adding key %llu value %lld...\n",
- tm->keys[i], (u64) (i + 1));
- fformat (stdout, "%U", BV (format_bihash), h,
- 2 /* very verbose */ );
+ u64 rndkey;
+
+ if (tm->non_random_keys == 0)
+ {
+
+ again:
+ rndkey = random_u64 (&tm->seed);
+
+ p = hash_get (tm->key_hash, rndkey);
+ if (p)
+ goto again;
+ }
+ else
+ rndkey = (u64) (i + 1) << 16;
+ rndkey += acycle;
+
+ hash_set (tm->key_hash, rndkey, i + 1);
+ vec_add1 (tm->keys, rndkey);
}
- }
- fformat (stdout, "%U", BV (format_bihash), h, 0 /* very verbose */ );
- fformat (stdout, "Search for items %d times...\n", tm->search_iter);
+ if ((acycle % tm->report_every_n) == 0)
+ fformat (stdout, "Add items...\n");
- before = clib_time_now (&tm->clib_time);
-
- for (j = 0; j < tm->search_iter; j++)
- {
for (i = 0; i < tm->nitems; i++)
{
kv.key = tm->keys[i];
- if (BV (clib_bihash_search) (h, &kv, &kv) < 0)
- if (BV (clib_bihash_search) (h, &kv, &kv) < 0)
- clib_warning ("[%d] search for key %lld failed unexpectedly\n",
- i, tm->keys[i]);
- if (kv.value != (u64) (i + 1))
- clib_warning
- ("[%d] search for key %lld returned %lld, not %lld\n", i,
- tm->keys, kv.value, (u64) (i + 1));
+ kv.value = i + 1;
+
+ BV (clib_bihash_add_del) (h, &kv, 1 /* is_add */ );
+
+ if (tm->verbose > 1)
+ {
+ fformat (stdout, "--------------------\n");
+ fformat (stdout, "After adding key %llu value %lld...\n",
+ tm->keys[i], (u64) (i + 1));
+ fformat (stdout, "%U", BV (format_bihash), h,
+ 2 /* very verbose */ );
+ }
}
- }
- delta = clib_time_now (&tm->clib_time) - before;
- total_searches = (uword) tm->search_iter * (uword) tm->nitems;
+ if ((acycle % tm->report_every_n) == 0)
+ {
+ fformat (stdout, "%U", BV (format_bihash), h,
+ 0 /* very verbose */ );
- if (delta > 0)
- fformat (stdout, "%.f searches per second\n",
- ((f64) total_searches) / delta);
+ fformat (stdout, "Search for items %d times...\n", tm->search_iter);
+ }
- fformat (stdout, "%lld searches in %.6f seconds\n", total_searches, delta);
+ before = clib_time_now (&tm->clib_time);
- fformat (stdout, "Standard E-hash search for items %d times...\n",
- tm->search_iter);
+ for (j = 0; j < tm->search_iter; j++)
+ {
+ for (i = 0; i < tm->nitems; i++)
+ {
+ kv.key = tm->keys[i];
+ if (BV (clib_bihash_search) (h, &kv, &kv) < 0)
+ if (BV (clib_bihash_search) (h, &kv, &kv) < 0)
+ clib_warning
+ ("[%d] search for key %lld failed unexpectedly\n", i,
+ tm->keys[i]);
+ if (kv.value != (u64) (i + 1))
+ clib_warning
+ ("[%d] search for key %lld returned %lld, not %lld\n", i,
+ tm->keys, kv.value, (u64) (i + 1));
+ }
+ }
- before = clib_time_now (&tm->clib_time);
+ if ((acycle % tm->report_every_n) == 0)
+ {
+ delta = clib_time_now (&tm->clib_time) - before;
+ total_searches = (uword) tm->search_iter * (uword) tm->nitems;
- for (j = 0; j < tm->search_iter; j++)
- {
+ if (delta > 0)
+ fformat (stdout, "%.f searches per second\n",
+ ((f64) total_searches) / delta);
+
+ fformat (stdout, "%lld searches in %.6f seconds\n", total_searches,
+ delta);
+
+ fformat (stdout, "Standard E-hash search for items %d times...\n",
+ tm->search_iter);
+ }
+
+ before = clib_time_now (&tm->clib_time);
+
+ for (j = 0; j < tm->search_iter; j++)
+ {
+ for (i = 0; i < tm->nitems; i++)
+ {
+ p = hash_get (tm->key_hash, tm->keys[i]);
+ if (p == 0 || p[0] != (uword) (i + 1))
+ clib_warning ("ugh, couldn't find %lld\n", tm->keys[i]);
+ }
+ }
+
+ delta = clib_time_now (&tm->clib_time) - before;
+ total_searches = (uword) tm->search_iter * (uword) tm->nitems;
+
+ if ((acycle % tm->report_every_n) == 0)
+ {
+ fformat (stdout, "%lld searches in %.6f seconds\n",
+ total_searches, delta);
+
+ if (delta > 0)
+ fformat (stdout, "%.f searches per second\n",
+ ((f64) total_searches) / delta);
+ fformat (stdout, "Delete items...\n");
+ }
+
for (i = 0; i < tm->nitems; i++)
{
- p = hash_get (tm->key_hash, tm->keys[i]);
- if (p == 0 || p[0] != (uword) (i + 1))
- clib_warning ("ugh, couldn't find %lld\n", tm->keys[i]);
- }
- }
+ int j;
+ int rv;
- delta = clib_time_now (&tm->clib_time) - before;
- total_searches = (uword) tm->search_iter * (uword) tm->nitems;
+ kv.key = tm->keys[i];
+ kv.value = (u64) (i + 1);
+ rv = BV (clib_bihash_add_del) (h, &kv, 0 /* is_add */ );
- fformat (stdout, "%lld searches in %.6f seconds\n", total_searches, delta);
+ if (rv < 0)
+ clib_warning ("delete key %lld not ok but should be",
+ tm->keys[i]);
- if (delta > 0)
- fformat (stdout, "%.f searches per second\n",
- ((f64) total_searches) / delta);
-
- fformat (stdout, "Delete items...\n");
-
- for (i = 0; i < tm->nitems; i++)
- {
- int j;
- int rv;
-
- kv.key = tm->keys[i];
- kv.value = (u64) (i + 1);
- rv = BV (clib_bihash_add_del) (h, &kv, 0 /* is_add */ );
-
- if (rv < 0)
- clib_warning ("delete key %lld not ok but should be", tm->keys[i]);
-
- if (tm->careful_delete_tests)
- {
- for (j = 0; j < tm->nitems; j++)
+ if (tm->careful_delete_tests)
{
- kv.key = tm->keys[j];
- rv = BV (clib_bihash_search) (h, &kv, &kv);
- if (j <= i && rv >= 0)
+ for (j = 0; j < tm->nitems; j++)
{
- clib_warning
- ("i %d j %d search ok but should not be, value %lld",
- i, j, kv.value);
- }
- if (j > i && rv < 0)
- {
- clib_warning ("i %d j %d search not ok but should be",
- i, j);
+ kv.key = tm->keys[j];
+ rv = BV (clib_bihash_search) (h, &kv, &kv);
+ if (j <= i && rv >= 0)
+ {
+ clib_warning
+ ("i %d j %d search ok but should not be, value %lld",
+ i, j, kv.value);
+ }
+ if (j > i && rv < 0)
+ {
+ clib_warning ("i %d j %d search not ok but should be",
+ i, j);
+ }
}
}
}
+ if ((acycle % tm->report_every_n) == 0)
+ {
+ struct rusage r_usage;
+ getrusage (RUSAGE_SELF, &r_usage);
+ fformat (stdout, "Kernel RSS: %ld bytes\n", r_usage.ru_maxrss);
+ fformat (stdout, "%U\n", BV (format_bihash), h, 0 /* verbose */ );
+ }
+
+ /* 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]);
+
+ vec_reset_length (tm->keys);
}
- fformat (stdout, "After deletions, should be empty...\n");
+ fformat (stdout, "End of run, should be empty...\n");
fformat (stdout, "%U", BV (format_bihash), h, 0 /* very verbose */ );
return 0;
@@ -276,6 +321,8 @@
clib_error_t *error;
int which = 0;
+ tm->report_every_n = 1;
+
while (unformat_check_input (i) != UNFORMAT_END_OF_INPUT)
{
if (unformat (i, "seed %u", &tm->seed))
@@ -287,12 +334,16 @@
tm->non_random_keys = 1;
else if (unformat (i, "nitems %d", &tm->nitems))
;
+ else if (unformat (i, "ncycles %d", &tm->ncycles))
+ ;
else if (unformat (i, "careful %d", &tm->careful_delete_tests))
;
else if (unformat (i, "verbose %d", &tm->verbose))
;
else if (unformat (i, "search %d", &tm->search_iter))
;
+ else if (unformat (i, "report-every %d", &tm->report_every_n))
+ ;
else if (unformat (i, "vec64"))
which = 1;
else if (unformat (i, "cache"))
@@ -341,6 +392,7 @@
tm->nbuckets = 2;
tm->nitems = 5;
+ tm->ncycles = 1;
tm->verbose = 1;
tm->search_iter = 1;
tm->careful_delete_tests = 0;