int zfs_no_write_throttle = 0;
int zfs_write_limit_shift = 3; /* 1/8th of physical memory */
int zfs_txg_synctime_ms = 1000; /* target millisecs to sync a txg */
+int zfs_txg_history = 60; /* statistics for the last N txgs */
unsigned long zfs_write_limit_min = 32 << 20; /* min write limit is 32MB */
unsigned long zfs_write_limit_max = 0; /* max data payload per txg */
static pgcnt_t old_physmem = 0;
+static int
+dsl_pool_txg_history_update(kstat_t *ksp, int rw)
+{
+ dsl_pool_t *dp = ksp->ks_private;
+ txg_history_t *th;
+ int i = 0;
+
+ if (rw == KSTAT_WRITE)
+ return (EACCES);
+
+ if (ksp->ks_data)
+ kmem_free(ksp->ks_data, ksp->ks_data_size);
+
+ mutex_enter(&dp->dp_lock);
+
+ ksp->ks_ndata = dp->dp_txg_history_size;
+ ksp->ks_data_size = dp->dp_txg_history_size * sizeof(kstat_txg_t);
+ if (ksp->ks_data_size > 0)
+ ksp->ks_data = kmem_alloc(ksp->ks_data_size, KM_PUSHPAGE);
+
+ /* Traversed oldest to youngest for the most readable kstat output */
+ for (th = list_tail(&dp->dp_txg_history); th != NULL;
+ th = list_prev(&dp->dp_txg_history, th)) {
+ mutex_enter(&th->th_lock);
+ ASSERT3S(i + sizeof(kstat_txg_t), <=, ksp->ks_data_size);
+ memcpy(ksp->ks_data + i, &th->th_kstat, sizeof(kstat_txg_t));
+ i += sizeof(kstat_txg_t);
+ mutex_exit(&th->th_lock);
+ }
+
+ mutex_exit(&dp->dp_lock);
+
+ return (0);
+}
+
+static void
+dsl_pool_txg_history_init(dsl_pool_t *dp, uint64_t txg)
+{
+ char name[KSTAT_STRLEN];
+
+ list_create(&dp->dp_txg_history, sizeof (txg_history_t),
+ offsetof(txg_history_t, th_link));
+ dsl_pool_txg_history_add(dp, txg);
+
+ (void) snprintf(name, KSTAT_STRLEN, "txgs-%s", spa_name(dp->dp_spa));
+ dp->dp_txg_kstat = kstat_create("zfs", 0, name, "misc",
+ KSTAT_TYPE_TXG, 0, KSTAT_FLAG_VIRTUAL);
+ if (dp->dp_txg_kstat) {
+ dp->dp_txg_kstat->ks_data = NULL;
+ dp->dp_txg_kstat->ks_private = dp;
+ dp->dp_txg_kstat->ks_update = dsl_pool_txg_history_update;
+ kstat_install(dp->dp_txg_kstat);
+ }
+}
+
+static void
+dsl_pool_txg_history_destroy(dsl_pool_t *dp)
+{
+ txg_history_t *th;
+
+ if (dp->dp_txg_kstat) {
+ if (dp->dp_txg_kstat->ks_data)
+ kmem_free(dp->dp_txg_kstat->ks_data,
+ dp->dp_txg_kstat->ks_data_size);
+
+ kstat_delete(dp->dp_txg_kstat);
+ }
+
+ mutex_enter(&dp->dp_lock);
+ while ((th = list_remove_head(&dp->dp_txg_history))) {
+ dp->dp_txg_history_size--;
+ mutex_destroy(&th->th_lock);
+ kmem_free(th, sizeof(txg_history_t));
+ }
+
+ ASSERT3U(dp->dp_txg_history_size, ==, 0);
+ list_destroy(&dp->dp_txg_history);
+ mutex_exit(&dp->dp_lock);
+}
+
+txg_history_t *
+dsl_pool_txg_history_add(dsl_pool_t *dp, uint64_t txg)
+{
+ txg_history_t *th, *rm;
+
+ th = kmem_zalloc(sizeof(txg_history_t), KM_SLEEP);
+ mutex_init(&th->th_lock, NULL, MUTEX_DEFAULT, NULL);
+ th->th_kstat.txg = txg;
+ th->th_kstat.state = TXG_STATE_OPEN;
+ th->th_kstat.birth = gethrtime();
+
+ mutex_enter(&dp->dp_lock);
+
+ list_insert_head(&dp->dp_txg_history, th);
+ dp->dp_txg_history_size++;
+
+ while (dp->dp_txg_history_size > zfs_txg_history) {
+ dp->dp_txg_history_size--;
+ rm = list_remove_tail(&dp->dp_txg_history);
+ mutex_destroy(&rm->th_lock);
+ kmem_free(rm, sizeof(txg_history_t));
+ }
+
+ mutex_exit(&dp->dp_lock);
+
+ return (th);
+}
+
+/*
+ * Traversed youngest to oldest because lookups are only done for open
+ * or syncing txgs which are guaranteed to be at the head of the list.
+ * The txg_history_t structure will be returned locked.
+ */
+txg_history_t *
+dsl_pool_txg_history_get(dsl_pool_t *dp, uint64_t txg)
+{
+ txg_history_t *th;
+
+ mutex_enter(&dp->dp_lock);
+ for (th = list_head(&dp->dp_txg_history); th != NULL;
+ th = list_next(&dp->dp_txg_history, th)) {
+ if (th->th_kstat.txg == txg) {
+ mutex_enter(&th->th_lock);
+ break;
+ }
+ }
+ mutex_exit(&dp->dp_lock);
+
+ return (th);
+}
+
+void
+dsl_pool_txg_history_put(txg_history_t *th)
+{
+ mutex_exit(&th->th_lock);
+}
+
int
dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp)
{
dp->dp_iput_taskq = taskq_create("zfs_iput_taskq", 1, minclsyspri,
1, 4, 0);
+ dsl_pool_txg_history_init(dp, txg);
+
return (dp);
}
arc_flush(dp->dp_spa);
txg_fini(dp);
dsl_scan_fini(dp);
+ dsl_pool_txg_history_destroy(dp);
rw_destroy(&dp->dp_config_rwlock);
mutex_destroy(&dp->dp_lock);
taskq_destroy(dp->dp_iput_taskq);
module_param(zfs_txg_synctime_ms, int, 0644);
MODULE_PARM_DESC(zfs_txg_synctime_ms, "Target milliseconds between txg sync");
+module_param(zfs_txg_history, int, 0644);
+MODULE_PARM_DESC(zfs_txg_history, "Historic statistics for the last N txgs");
+
module_param(zfs_write_limit_min, ulong, 0444);
MODULE_PARM_DESC(zfs_write_limit_min, "Min txg write limit");
#include <sys/dsl_pool.h>
#include <sys/dsl_scan.h>
#include <sys/callb.h>
+#include <sys/spa_impl.h>
/*
* Pool-wide transaction groups.
static void
txg_quiesce(dsl_pool_t *dp, uint64_t txg)
{
+ hrtime_t start;
+ txg_history_t *th;
tx_state_t *tx = &dp->dp_tx;
int g = txg & TXG_MASK;
int c;
ASSERT(txg == tx->tx_open_txg);
tx->tx_open_txg++;
+ /*
+ * Measure how long the txg was open and replace the kstat.
+ */
+ th = dsl_pool_txg_history_get(dp, txg);
+ th->th_kstat.open_time = gethrtime() - th->th_kstat.birth;
+ th->th_kstat.state = TXG_STATE_QUIESCING;
+ dsl_pool_txg_history_put(th);
+ dsl_pool_txg_history_add(dp, tx->tx_open_txg);
+
/*
* Now that we've incremented tx_open_txg, we can let threads
* enter the next transaction group.
/*
* Quiesce the transaction group by waiting for everyone to txg_exit().
*/
+ start = gethrtime();
+
for (c = 0; c < max_ncpus; c++) {
tx_cpu_t *tc = &tx->tx_cpu[c];
mutex_enter(&tc->tc_lock);
cv_wait(&tc->tc_cv[g], &tc->tc_lock);
mutex_exit(&tc->tc_lock);
}
+
+ /*
+ * Measure how long the txg took to quiesce.
+ */
+ th = dsl_pool_txg_history_get(dp, txg);
+ th->th_kstat.quiesce_time = gethrtime() - start;
+ dsl_pool_txg_history_put(th);
}
static void
start = delta = 0;
for (;;) {
+ hrtime_t hrstart;
+ txg_history_t *th;
uint64_t timer, timeout;
uint64_t txg;
tx->tx_syncing_txg = txg;
cv_broadcast(&tx->tx_quiesce_more_cv);
+ th = dsl_pool_txg_history_get(dp, txg);
+ th->th_kstat.state = TXG_STATE_SYNCING;
+ vdev_get_stats(spa->spa_root_vdev, &th->th_vs1);
+ dsl_pool_txg_history_put(th);
+
dprintf("txg=%llu quiesce_txg=%llu sync_txg=%llu\n",
txg, tx->tx_quiesce_txg_waiting, tx->tx_sync_txg_waiting);
mutex_exit(&tx->tx_sync_lock);
start = ddi_get_lbolt();
+ hrstart = gethrtime();
spa_sync(spa, txg);
delta = ddi_get_lbolt() - start;
* Dispatch commit callbacks to worker threads.
*/
txg_dispatch_callbacks(dp, txg);
+
+ /*
+ * Measure the txg sync time determine the amount of I/O done.
+ */
+ th = dsl_pool_txg_history_get(dp, txg);
+ vdev_get_stats(spa->spa_root_vdev, &th->th_vs2);
+ th->th_kstat.sync_time = gethrtime() - hrstart;
+ th->th_kstat.nread = th->th_vs2.vs_bytes[ZIO_TYPE_READ] -
+ th->th_vs1.vs_bytes[ZIO_TYPE_READ];
+ th->th_kstat.nwritten = th->th_vs2.vs_bytes[ZIO_TYPE_WRITE] -
+ th->th_vs1.vs_bytes[ZIO_TYPE_WRITE];
+ th->th_kstat.reads = th->th_vs2.vs_ops[ZIO_TYPE_READ] -
+ th->th_vs1.vs_ops[ZIO_TYPE_READ];
+ th->th_kstat.writes = th->th_vs2.vs_ops[ZIO_TYPE_WRITE] -
+ th->th_vs1.vs_ops[ZIO_TYPE_WRITE];
+ th->th_kstat.state = TXG_STATE_COMMITTED;
+ dsl_pool_txg_history_put(th);
}
}
projects / zfs / commitdiff