mirror of
https://git.proxmox.com/git/mirror_zfs.git
synced 2024-12-25 18:59:33 +03:00
Add new kstat for monitoring time in dmu_tx_assign
This change adds a new kstat to gain some visibility into the amount of
time spent in each call to dmu_tx_assign. A histogram is exported via
a new dmu_tx_assign_histogram-$POOLNAME file. The information contained
in this histogram is the frequency dmu_tx_assign took to complete given
an interval range. For example, given the below histogram file:
$ cat /proc/spl/kstat/zfs/dmu_tx_assign_histogram-tank
12 1 0x01 32 1536 19792068076691 20516481514522
name type data
1 us 4 859
2 us 4 252
4 us 4 171
8 us 4 2
16 us 4 0
32 us 4 2
64 us 4 0
128 us 4 0
256 us 4 0
512 us 4 0
1024 us 4 0
2048 us 4 0
4096 us 4 0
8192 us 4 0
16384 us 4 0
32768 us 4 1
65536 us 4 1
131072 us 4 1
262144 us 4 4
524288 us 4 0
1048576 us 4 0
2097152 us 4 0
4194304 us 4 0
8388608 us 4 0
16777216 us 4 0
33554432 us 4 0
67108864 us 4 0
134217728 us 4 0
268435456 us 4 0
536870912 us 4 0
1073741824 us 4 0
2147483648 us 4 0
one can see most calls to dmu_tx_assign completed in 32us or less, but a
few outliers did not. Specifically, 4 of the calls took between 262144us
and 131072us. This information is difficult, if not impossible, to gather
without this change.
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1584
This commit is contained in:
Prakash Surya
Brian Behlendorf
parent
bf89c19914
commit
92334b14ec
@ -89,6 +89,7 @@ typedef struct dsl_pool {
|
||||
uint64_t dp_root_dir_obj;
|
||||
struct taskq *dp_iput_taskq;
|
||||
kstat_t *dp_txg_kstat;
|
||||
kstat_t *dp_tx_assign_kstat;
|
||||
|
||||
/* No lock needed - sync context only */
|
||||
blkptr_t dp_meta_rootbp;
|
||||
@ -111,6 +112,8 @@ typedef struct dsl_pool {
|
||||
uint64_t dp_mos_uncompressed_delta;
|
||||
uint64_t dp_txg_history_size;
|
||||
list_t dp_txg_history;
|
||||
uint64_t dp_tx_assign_size;
|
||||
kstat_named_t *dp_tx_assign_buckets;
|
||||
|
||||
|
||||
/* Has its own locking */
|
||||
@ -162,6 +165,8 @@ extern int dsl_pool_user_release(dsl_pool_t *dp, uint64_t dsobj,
|
||||
extern void dsl_pool_clean_tmp_userrefs(dsl_pool_t *dp);
|
||||
int dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **);
|
||||
|
||||
void dsl_pool_tx_assign_add_usecs(dsl_pool_t *dp, uint64_t usecs);
|
||||
|
||||
txg_history_t *dsl_pool_txg_history_add(dsl_pool_t *dp, uint64_t txg);
|
||||
txg_history_t *dsl_pool_txg_history_get(dsl_pool_t *dp, uint64_t txg);
|
||||
void dsl_pool_txg_history_put(txg_history_t *th);
|
||||
|
||||
@ -1089,12 +1089,15 @@ dmu_tx_unassign(dmu_tx_t *tx)
|
||||
int
|
||||
dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how)
|
||||
{
|
||||
hrtime_t before, after;
|
||||
int err;
|
||||
|
||||
ASSERT(tx->tx_txg == 0);
|
||||
ASSERT(txg_how != 0);
|
||||
ASSERT(!dsl_pool_sync_context(tx->tx_pool));
|
||||
|
||||
before = gethrtime();
|
||||
|
||||
while ((err = dmu_tx_try_assign(tx, txg_how)) != 0) {
|
||||
dmu_tx_unassign(tx);
|
||||
|
||||
@ -1106,6 +1109,11 @@ dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how)
|
||||
|
||||
txg_rele_to_quiesce(&tx->tx_txgh);
|
||||
|
||||
after = gethrtime();
|
||||
|
||||
dsl_pool_tx_assign_add_usecs(tx->tx_pool,
|
||||
(after - before) / NSEC_PER_USEC);
|
||||
|
||||
return (0);
|
||||
}
|
||||
|
||||
|
||||
@ -58,6 +58,63 @@ kmutex_t zfs_write_limit_lock;
|
||||
|
||||
static pgcnt_t old_physmem = 0;
|
||||
|
||||
static void
|
||||
dsl_pool_tx_assign_init(dsl_pool_t *dp, unsigned int ndata)
|
||||
{
|
||||
kstat_named_t *ks;
|
||||
char name[KSTAT_STRLEN];
|
||||
int i, data_size = ndata * sizeof(kstat_named_t);
|
||||
|
||||
(void) snprintf(name, KSTAT_STRLEN, "dmu_tx_assign-%s",
|
||||
spa_name(dp->dp_spa));
|
||||
|
||||
dp->dp_tx_assign_size = ndata;
|
||||
|
||||
if (data_size)
|
||||
dp->dp_tx_assign_buckets = kmem_alloc(data_size, KM_SLEEP);
|
||||
else
|
||||
dp->dp_tx_assign_buckets = NULL;
|
||||
|
||||
for (i = 0; i < dp->dp_tx_assign_size; i++) {
|
||||
ks = &dp->dp_tx_assign_buckets[i];
|
||||
ks->data_type = KSTAT_DATA_UINT64;
|
||||
ks->value.ui64 = 0;
|
||||
(void) snprintf(ks->name, KSTAT_STRLEN, "%u us", 1 << i);
|
||||
}
|
||||
|
||||
dp->dp_tx_assign_kstat = kstat_create("zfs", 0, name, "misc",
|
||||
KSTAT_TYPE_NAMED, 0, KSTAT_FLAG_VIRTUAL);
|
||||
|
||||
if (dp->dp_tx_assign_kstat) {
|
||||
dp->dp_tx_assign_kstat->ks_data = dp->dp_tx_assign_buckets;
|
||||
dp->dp_tx_assign_kstat->ks_ndata = dp->dp_tx_assign_size;
|
||||
dp->dp_tx_assign_kstat->ks_data_size = data_size;
|
||||
kstat_install(dp->dp_tx_assign_kstat);
|
||||
}
|
||||
}
|
||||
|
||||
static void
|
||||
dsl_pool_tx_assign_destroy(dsl_pool_t *dp)
|
||||
{
|
||||
if (dp->dp_tx_assign_buckets)
|
||||
kmem_free(dp->dp_tx_assign_buckets,
|
||||
dp->dp_tx_assign_size * sizeof(kstat_named_t));
|
||||
|
||||
if (dp->dp_tx_assign_kstat)
|
||||
kstat_delete(dp->dp_tx_assign_kstat);
|
||||
}
|
||||
|
||||
void
|
||||
dsl_pool_tx_assign_add_usecs(dsl_pool_t *dp, uint64_t usecs)
|
||||
{
|
||||
uint64_t idx = 0;
|
||||
|
||||
while (((1 << idx) < usecs) && (idx < dp->dp_tx_assign_size - 1))
|
||||
idx++;
|
||||
|
||||
atomic_inc_64(&dp->dp_tx_assign_buckets[idx].value.ui64);
|
||||
}
|
||||
|
||||
static int
|
||||
dsl_pool_txg_history_update(kstat_t *ksp, int rw)
|
||||
{
|
||||
@ -238,6 +295,7 @@ dsl_pool_open_impl(spa_t *spa, uint64_t txg)
|
||||
1, 4, 0);
|
||||
|
||||
dsl_pool_txg_history_init(dp, txg);
|
||||
dsl_pool_tx_assign_init(dp, 32);
|
||||
|
||||
return (dp);
|
||||
}
|
||||
@ -379,6 +437,7 @@ dsl_pool_close(dsl_pool_t *dp)
|
||||
arc_flush(dp->dp_spa);
|
||||
txg_fini(dp);
|
||||
dsl_scan_fini(dp);
|
||||
dsl_pool_tx_assign_destroy(dp);
|
||||
dsl_pool_txg_history_destroy(dp);
|
||||
rw_destroy(&dp->dp_config_rwlock);
|
||||
mutex_destroy(&dp->dp_lock);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user