diff options
Diffstat (limited to 'lib/ccan/htable/tools/speed.c')
| -rw-r--r-- | lib/ccan/htable/tools/speed.c | 377 |
1 files changed, 377 insertions, 0 deletions
diff --git a/lib/ccan/htable/tools/speed.c b/lib/ccan/htable/tools/speed.c new file mode 100644 index 0000000000..26231924a1 --- /dev/null +++ b/lib/ccan/htable/tools/speed.c @@ -0,0 +1,377 @@ +/* Simple speed tests for hashtables. */ +#include <ccan/htable/htable_type.h> +#include <ccan/htable/htable.c> +#include <ccan/hash/hash.h> +#include <stdio.h> +#include <stdlib.h> +#include <time.h> +#include <unistd.h> +#include <sys/time.h> + +static size_t hashcount; +struct object { + /* The key. */ + unsigned int key; + + /* Some contents. Doubles as consistency check. */ + struct object *self; +}; + +static const unsigned int *objkey(const struct object *obj) +{ + return &obj->key; +} + +static size_t hash_obj(const unsigned int *key) +{ + hashcount++; + return hashl(key, 1, 0); +} + +static bool cmp(const unsigned int *key1, const unsigned int *key2) +{ + return *key1 == *key2; +} + +HTABLE_DEFINE_TYPE(struct object, objkey, hash_obj, cmp, obj); + +static unsigned int popcount(unsigned long val) +{ +#if HAVE_BUILTIN_POPCOUNTL + return __builtin_popcountl(val); +#else + if (sizeof(long) == sizeof(u64)) { + u64 v = val; + v = (v & 0x5555555555555555ULL) + + ((v >> 1) & 0x5555555555555555ULL); + v = (v & 0x3333333333333333ULL) + + ((v >> 1) & 0x3333333333333333ULL); + v = (v & 0x0F0F0F0F0F0F0F0FULL) + + ((v >> 1) & 0x0F0F0F0F0F0F0F0FULL); + v = (v & 0x00FF00FF00FF00FFULL) + + ((v >> 1) & 0x00FF00FF00FF00FFULL); + v = (v & 0x0000FFFF0000FFFFULL) + + ((v >> 1) & 0x0000FFFF0000FFFFULL); + v = (v & 0x00000000FFFFFFFFULL) + + ((v >> 1) & 0x00000000FFFFFFFFULL); + return v; + } + val = (val & 0x55555555ULL) + ((val >> 1) & 0x55555555ULL); + val = (val & 0x33333333ULL) + ((val >> 1) & 0x33333333ULL); + val = (val & 0x0F0F0F0FULL) + ((val >> 1) & 0x0F0F0F0FULL); + val = (val & 0x00FF00FFULL) + ((val >> 1) & 0x00FF00FFULL); + val = (val & 0x0000FFFFULL) + ((val >> 1) & 0x0000FFFFULL); + return val; +#endif +} + +static size_t perfect(const struct htable *ht) +{ + size_t i, placed_perfect = 0; + + for (i = 0; i < ((size_t)1 << ht->bits); i++) { + if (!entry_is_valid(ht->table[i])) + continue; + if (hash_bucket(ht, ht->rehash(get_raw_ptr(ht, ht->table[i]), + ht->priv)) == i) { + assert((ht->table[i] & ht->perfect_bit) + == ht->perfect_bit); + placed_perfect++; + } + } + return placed_perfect; +} + +static size_t count_deleted(const struct htable *ht) +{ + size_t i, delete_markers = 0; + + for (i = 0; i < ((size_t)1 << ht->bits); i++) { + if (ht->table[i] == HTABLE_DELETED) + delete_markers++; + } + return delete_markers; +} + +/* Nanoseconds per operation */ +static size_t normalize(const struct timeval *start, + const struct timeval *stop, + unsigned int num) +{ + struct timeval diff; + + timersub(stop, start, &diff); + + /* Floating point is more accurate here. */ + return (double)(diff.tv_sec * 1000000 + diff.tv_usec) + / num * 1000; +} + +static size_t worst_run(struct htable *ht, size_t *deleted) +{ + size_t longest = 0, len = 0, this_del = 0, i; + + *deleted = 0; + /* This doesn't take into account end-wrap, but gives an idea. */ + for (i = 0; i < ((size_t)1 << ht->bits); i++) { + if (ht->table[i]) { + len++; + if (ht->table[i] == HTABLE_DELETED) + this_del++; + } else { + if (len > longest) { + longest = len; + *deleted = this_del; + } + len = 0; + this_del = 0; + } + } + return longest; +} + +int main(int argc, char *argv[]) +{ + struct object *objs; + size_t i, j, num, deleted; + struct timeval start, stop; + struct htable_obj *ht; + struct htable *htr; + bool make_dumb = false; + + if (argv[1] && strcmp(argv[1], "--dumb") == 0) { + argv++; + make_dumb = true; + } + num = argv[1] ? atoi(argv[1]) : 1000000; + objs = calloc(num, sizeof(objs[0])); + + for (i = 0; i < num; i++) { + objs[i].key = i; + objs[i].self = &objs[i]; + } + + ht = htable_obj_new(); + htr = (void *)ht; + + printf("Initial insert: "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0; i < num; i++) + htable_obj_add(ht, objs[i].self); + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + printf("Details: hash size %u, mask bits %u, perfect %.0f%%\n", + 1U << htr->bits, popcount(htr->common_mask), + perfect(htr) * 100.0 / htr->elems); + + if (make_dumb) { + /* Screw with mask, to hobble us. */ + update_common(htr, (void *)~htr->common_bits); + printf("Details: DUMB MODE: mask bits %u\n", + popcount(htr->common_mask)); + } + + printf("Initial lookup (match): "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0; i < num; i++) + if (htable_obj_get(ht, &i)->self != objs[i].self) + abort(); + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + printf("Initial lookup (miss): "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0; i < num; i++) { + unsigned int n = i + num; + if (htable_obj_get(ht, &n)) + abort(); + } + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + /* Lookups in order are very cache-friendly for judy; try random */ + printf("Initial lookup (random): "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0, j = 0; i < num; i++, j = (j + 10007) % num) + if (htable_obj_get(ht, &j)->self != &objs[j]) + abort(); + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + hashcount = 0; + printf("Initial delete all: "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0; i < num; i++) + if (!htable_obj_del(ht, objs[i].self)) + abort(); + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + printf("Details: rehashes %zu\n", hashcount); + + printf("Initial re-inserting: "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0; i < num; i++) + htable_obj_add(ht, objs[i].self); + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + hashcount = 0; + printf("Deleting first half: "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0; i < num; i+=2) + if (!htable_obj_del(ht, objs[i].self)) + abort(); + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + printf("Details: rehashes %zu, delete markers %zu\n", + hashcount, count_deleted(htr)); + + printf("Adding (a different) half: "); + fflush(stdout); + + for (i = 0; i < num; i+=2) + objs[i].key = num+i; + + gettimeofday(&start, NULL); + for (i = 0; i < num; i+=2) + htable_obj_add(ht, objs[i].self); + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + printf("Details: delete markers %zu, perfect %.0f%%\n", + count_deleted(htr), perfect(htr) * 100.0 / htr->elems); + + printf("Lookup after half-change (match): "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 1; i < num; i+=2) + if (htable_obj_get(ht, &i)->self != objs[i].self) + abort(); + for (i = 0; i < num; i+=2) { + unsigned int n = i + num; + if (htable_obj_get(ht, &n)->self != objs[i].self) + abort(); + } + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + printf("Lookup after half-change (miss): "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0; i < num; i++) { + unsigned int n = i + num * 2; + if (htable_obj_get(ht, &n)) + abort(); + } + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + /* Hashtables with delete markers can fill with markers over time. + * so do some changes to see how it operates in long-term. */ + for (i = 0; i < 5; i++) { + if (i == 0) { + /* We don't measure this: jmap is different. */ + printf("Details: initial churn\n"); + } else { + printf("Churning %s time: ", + i == 1 ? "second" + : i == 2 ? "third" + : i == 3 ? "fourth" + : "fifth"); + fflush(stdout); + } + gettimeofday(&start, NULL); + for (j = 0; j < num; j++) { + if (!htable_obj_del(ht, &objs[j])) + abort(); + objs[j].key = num*i+j; + if (!htable_obj_add(ht, &objs[j])) + abort(); + } + gettimeofday(&stop, NULL); + if (i != 0) + printf(" %zu ns\n", normalize(&start, &stop, num)); + } + + /* Spread out the keys more to try to make it harder. */ + printf("Details: reinserting with spread\n"); + for (i = 0; i < num; i++) { + if (!htable_obj_del(ht, objs[i].self)) + abort(); + objs[i].key = num * 5 + i * 9; + if (!htable_obj_add(ht, objs[i].self)) + abort(); + } + printf("Details: delete markers %zu, perfect %.0f%%\n", + count_deleted(htr), perfect(htr) * 100.0 / htr->elems); + i = worst_run(htr, &deleted); + printf("Details: worst run %zu (%zu deleted)\n", i, deleted); + + printf("Lookup after churn & spread (match): "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0; i < num; i++) { + unsigned int n = num * 5 + i * 9; + if (htable_obj_get(ht, &n)->self != objs[i].self) + abort(); + } + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + printf("Lookup after churn & spread (miss): "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0; i < num; i++) { + unsigned int n = num * (5 + 9) + i * 9; + if (htable_obj_get(ht, &n)) + abort(); + } + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + printf("Lookup after churn & spread (random): "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0, j = 0; i < num; i++, j = (j + 10007) % num) { + unsigned int n = num * 5 + j * 9; + if (htable_obj_get(ht, &n)->self != &objs[j]) + abort(); + } + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + hashcount = 0; + printf("Deleting half after churn & spread: "); + fflush(stdout); + gettimeofday(&start, NULL); + for (i = 0; i < num; i+=2) + if (!htable_obj_del(ht, objs[i].self)) + abort(); + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + printf("Adding (a different) half after churn & spread: "); + fflush(stdout); + + for (i = 0; i < num; i+=2) + objs[i].key = num*6+i*9; + + gettimeofday(&start, NULL); + for (i = 0; i < num; i+=2) + htable_obj_add(ht, objs[i].self); + gettimeofday(&stop, NULL); + printf(" %zu ns\n", normalize(&start, &stop, num)); + + printf("Details: delete markers %zu, perfect %.0f%%\n", + count_deleted(htr), perfect(htr) * 100.0 / htr->elems); + + return 0; +} |