c/mirror_zfs
1
0
Fork 0
mirror of https://git.proxmox.com/git/mirror_zfs.git synced 2026-05-25 11:47:43 +03:00
Code Issues Packages Projects Releases Wiki Activity

Use wmsum for arc, abd, dbuf and zfetch statistics. (#12172)

Browse Source 
wmsum was designed exactly for cases like these with many updates
and rare reads.  It allows to completely avoid atomic operations on
congested global variables.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #12172
This commit is contained in:
Alexander Motin
2021-06-16 20:19:34 -04:00
committed by GitHub
parent 9ffcaa370a
commit c4c162c1e8
8 changed files with 777 additions and 215 deletions
Download Patch File Download Diff File Expand all files Collapse all files
module/zfs/dbuf.c
+87 -25
View File
@@ -52,6 +52,7 @@
#include <sys/vdev.h>
#include <cityhash.h>
#include <sys/spa_impl.h>
#include <sys/wmsum.h>
kstat_t *dbuf_ksp;
@@ -135,8 +136,22 @@ dbuf_stats_t dbuf_stats = {
{ "metadata_cache_overflow", KSTAT_DATA_UINT64 }
};
struct {
wmsum_t cache_count;
wmsum_t cache_total_evicts;
wmsum_t cache_levels[DN_MAX_LEVELS];
wmsum_t cache_levels_bytes[DN_MAX_LEVELS];
wmsum_t hash_hits;
wmsum_t hash_misses;
wmsum_t hash_collisions;
wmsum_t hash_chains;
wmsum_t hash_insert_race;
wmsum_t metadata_cache_count;
wmsum_t metadata_cache_overflow;
} dbuf_sums;
#define DBUF_STAT_INCR(stat, val) \
atomic_add_64(&dbuf_stats.stat.value.ui64, (val));
wmsum_add(&dbuf_sums.stat, val);
#define DBUF_STAT_DECR(stat, val) \
DBUF_STAT_INCR(stat, -(val));
#define DBUF_STAT_BUMP(stat) \
@@ -297,8 +312,6 @@ dbuf_dest(void *vdb, void *unused)
*/
static dbuf_hash_table_t dbuf_hash_table;
static uint64_t dbuf_hash_count;
/*
* We use Cityhash for this. It's fast, and has good hash properties without
* requiring any large static buffers.
@@ -409,8 +422,8 @@ dbuf_hash_insert(dmu_buf_impl_t *db)
db->db_hash_next = h->hash_table[idx];
h->hash_table[idx] = db;
mutex_exit(DBUF_HASH_MUTEX(h, idx));
atomic_inc_64(&dbuf_hash_count);
DBUF_STAT_MAX(hash_elements_max, dbuf_hash_count);
uint64_t he = atomic_inc_64_nv(&dbuf_stats.hash_elements.value.ui64);
DBUF_STAT_MAX(hash_elements_max, he);
return (NULL);
}
@@ -483,7 +496,7 @@ dbuf_hash_remove(dmu_buf_impl_t *db)
h->hash_table[idx]->db_hash_next == NULL)
DBUF_STAT_BUMPDOWN(hash_chains);
mutex_exit(DBUF_HASH_MUTEX(h, idx));
atomic_dec_64(&dbuf_hash_count);
atomic_dec_64(&dbuf_stats.hash_elements.value.ui64);
}
typedef enum {
@@ -767,19 +780,40 @@ dbuf_kstat_update(kstat_t *ksp, int rw)
{
dbuf_stats_t *ds = ksp->ks_data;
if (rw == KSTAT_WRITE) {
if (rw == KSTAT_WRITE)
return (SET_ERROR(EACCES));
} else {
ds->metadata_cache_size_bytes.value.ui64 = zfs_refcount_count(
&dbuf_caches[DB_DBUF_METADATA_CACHE].size);
ds->cache_size_bytes.value.ui64 =
zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size);
ds->cache_target_bytes.value.ui64 = dbuf_cache_target_bytes();
ds->cache_hiwater_bytes.value.ui64 = dbuf_cache_hiwater_bytes();
ds->cache_lowater_bytes.value.ui64 = dbuf_cache_lowater_bytes();
ds->hash_elements.value.ui64 = dbuf_hash_count;
}
ds->cache_count.value.ui64 =
wmsum_value(&dbuf_sums.cache_count);
ds->cache_size_bytes.value.ui64 =
zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size);
ds->cache_target_bytes.value.ui64 = dbuf_cache_target_bytes();
ds->cache_hiwater_bytes.value.ui64 = dbuf_cache_hiwater_bytes();
ds->cache_lowater_bytes.value.ui64 = dbuf_cache_lowater_bytes();
ds->cache_total_evicts.value.ui64 =
wmsum_value(&dbuf_sums.cache_total_evicts);
for (int i = 0; i < DN_MAX_LEVELS; i++) {
ds->cache_levels[i].value.ui64 =
wmsum_value(&dbuf_sums.cache_levels[i]);
ds->cache_levels_bytes[i].value.ui64 =
wmsum_value(&dbuf_sums.cache_levels_bytes[i]);
}
ds->hash_hits.value.ui64 =
wmsum_value(&dbuf_sums.hash_hits);
ds->hash_misses.value.ui64 =
wmsum_value(&dbuf_sums.hash_misses);
ds->hash_collisions.value.ui64 =
wmsum_value(&dbuf_sums.hash_collisions);
ds->hash_chains.value.ui64 =
wmsum_value(&dbuf_sums.hash_chains);
ds->hash_insert_race.value.ui64 =
wmsum_value(&dbuf_sums.hash_insert_race);
ds->metadata_cache_count.value.ui64 =
wmsum_value(&dbuf_sums.metadata_cache_count);
ds->metadata_cache_size_bytes.value.ui64 = zfs_refcount_count(
&dbuf_caches[DB_DBUF_METADATA_CACHE].size);
ds->metadata_cache_overflow.value.ui64 =
wmsum_value(&dbuf_sums.metadata_cache_overflow);
return (0);
}
@@ -846,6 +880,20 @@ retry:
dbuf_cache_evict_thread = thread_create(NULL, 0, dbuf_evict_thread,
NULL, 0, &p0, TS_RUN, minclsyspri);
wmsum_init(&dbuf_sums.cache_count, 0);
wmsum_init(&dbuf_sums.cache_total_evicts, 0);
for (i = 0; i < DN_MAX_LEVELS; i++) {
wmsum_init(&dbuf_sums.cache_levels[i], 0);
wmsum_init(&dbuf_sums.cache_levels_bytes[i], 0);
}
wmsum_init(&dbuf_sums.hash_hits, 0);
wmsum_init(&dbuf_sums.hash_misses, 0);
wmsum_init(&dbuf_sums.hash_collisions, 0);
wmsum_init(&dbuf_sums.hash_chains, 0);
wmsum_init(&dbuf_sums.hash_insert_race, 0);
wmsum_init(&dbuf_sums.metadata_cache_count, 0);
wmsum_init(&dbuf_sums.metadata_cache_overflow, 0);
dbuf_ksp = kstat_create("zfs", 0, "dbufstats", "misc",
KSTAT_TYPE_NAMED, sizeof (dbuf_stats) / sizeof (kstat_named_t),
KSTAT_FLAG_VIRTUAL);
@@ -908,6 +956,20 @@ dbuf_fini(void)
kstat_delete(dbuf_ksp);
dbuf_ksp = NULL;
}
wmsum_fini(&dbuf_sums.cache_count);
wmsum_fini(&dbuf_sums.cache_total_evicts);
for (i = 0; i < DN_MAX_LEVELS; i++) {
wmsum_fini(&dbuf_sums.cache_levels[i]);
wmsum_fini(&dbuf_sums.cache_levels_bytes[i]);
}
wmsum_fini(&dbuf_sums.hash_hits);
wmsum_fini(&dbuf_sums.hash_misses);
wmsum_fini(&dbuf_sums.hash_collisions);
wmsum_fini(&dbuf_sums.hash_chains);
wmsum_fini(&dbuf_sums.hash_insert_race);
wmsum_fini(&dbuf_sums.metadata_cache_count);
wmsum_fini(&dbuf_sums.metadata_cache_overflow);
}
/*
@@ -3708,9 +3770,11 @@ dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag, boolean_t evicting)
db->db_caching_status = dcs;
multilist_insert(&dbuf_caches[dcs].cache, db);
uint64_t db_size = db->db.db_size;
size = zfs_refcount_add_many(
&dbuf_caches[dcs].size,
db->db.db_size, db);
&dbuf_caches[dcs].size, db_size, db);
uint8_t db_level = db->db_level;
mutex_exit(&db->db_mtx);
if (dcs == DB_DBUF_METADATA_CACHE) {
DBUF_STAT_BUMP(metadata_cache_count);
@@ -3718,16 +3782,14 @@ dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag, boolean_t evicting)
metadata_cache_size_bytes_max,
size);
} else {
DBUF_STAT_BUMP(
cache_levels[db->db_level]);
DBUF_STAT_BUMP(cache_count);
DBUF_STAT_INCR(
cache_levels_bytes[db->db_level],
db->db.db_size);
DBUF_STAT_MAX(cache_size_bytes_max,
size);
DBUF_STAT_BUMP(cache_levels[db_level]);
DBUF_STAT_INCR(
cache_levels_bytes[db_level],
db_size);
}
mutex_exit(&db->db_mtx);
if (dcs == DB_DBUF_CACHE && !evicting)
dbuf_evict_notify(size);