Revert "Add txgs-<pool> kstat file"

This reverts commit e95853a331.

include/sys/dsl_pool.h

@@ -71,13 +71,6 @@ typedef struct zfs_all_blkstats {
 	zfs_blkstat_t	zab_type[DN_MAX_LEVELS + 1][DMU_OT_TOTAL + 1];
 } zfs_all_blkstats_t;
 
-typedef struct txg_history {
-	kstat_txg_t	th_kstat;
-	vdev_stat_t	th_vs1;
-	vdev_stat_t	th_vs2;
-	kmutex_t	th_lock;
-	list_node_t	th_link;
-} txg_history_t;
 
 typedef struct dsl_pool {
 	/* Immutable */
@@ -89,7 +82,6 @@ typedef struct dsl_pool {
 	struct dsl_dataset *dp_origin_snap;
 	uint64_t dp_root_dir_obj;
 	struct taskq *dp_iput_taskq;
-	kstat_t *dp_txg_kstat;
 
 	/* No lock needed - sync context only */
 	blkptr_t dp_meta_rootbp;
@@ -110,9 +102,6 @@ typedef struct dsl_pool {
 	uint64_t dp_mos_used_delta;
 	uint64_t dp_mos_compressed_delta;
 	uint64_t dp_mos_uncompressed_delta;
-	uint64_t dp_txg_history_size;
-	list_t dp_txg_history;
-
 
 	/* Has its own locking */
 	tx_state_t dp_tx;
@@ -168,10 +157,6 @@ int dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **);
 int dsl_pool_hold(const char *name, void *tag, dsl_pool_t **dp);
 void dsl_pool_rele(dsl_pool_t *dp, void *tag);
 
-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);
-
 #ifdef	__cplusplus
 }
 #endif

lib/libspl/include/sys/kstat.h

@@ -228,10 +228,8 @@ typedef struct kstat32 {
 					/* ks_ndata == 1 */
 #define	KSTAT_TYPE_TIMER	4	/* event timer */
 					/* ks_ndata >= 1 */
-#define	KSTAT_TYPE_TXG		5	/* txg statistics */
-					/* ks_ndata >= 0 */
 
-#define	KSTAT_NUM_TYPES		6
+#define	KSTAT_NUM_TYPES		5
 
 /*
  * kstat class
@@ -700,29 +698,6 @@ typedef struct kstat_timer {
 
 #define	KSTAT_TIMER_PTR(kptr)	((kstat_timer_t *)(kptr)->ks_data)
 
-/*
- * TXG statistics - bytes read/written and iops performed
- */
-typedef enum kstat_txg_state {
-	TXG_STATE_OPEN      = 1,
-	TXG_STATE_QUIESCING = 2,
-	TXG_STATE_SYNCING   = 3,
-	TXG_STATE_COMMITTED = 4,
-} kstat_txg_state_t;
-
-typedef struct kstat_txg {
-	u_longlong_t		txg;		/* txg id */
-	kstat_txg_state_t	state;		/* txg state */
-	hrtime_t		birth;		/* birth time stamp */
-	u_longlong_t		nread;		/* number of bytes read */
-	u_longlong_t		nwritten;	/* number of bytes written */
-	uint_t			reads;		/* number of read operations */
-	uint_t			writes;		/* number of write operations */
-	hrtime_t		open_time;	/* open time */
-	hrtime_t		quiesce_time;	/* quiesce time */
-	hrtime_t		sync_time;	/* sync time */
-} kstat_txg_t;
-
 #if	defined(_KERNEL)
 
 #include <sys/t_lock.h>

module/zfs/dsl_pool.c

@@ -48,7 +48,6 @@
 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 */
@@ -59,143 +58,6 @@ kmutex_t zfs_write_limit_lock;
 
 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_PUSHPAGE);
-	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)
 {
@@ -238,8 +100,6 @@ dsl_pool_open_impl(spa_t *spa, uint64_t txg)
 	dp->dp_iput_taskq = taskq_create("zfs_iput_taskq", 1, minclsyspri,
 	    1, 4, 0);
 
-	dsl_pool_txg_history_init(dp, txg);
-
 	return (dp);
 }
 
@@ -380,7 +240,6 @@ dsl_pool_close(dsl_pool_t *dp)
 	arc_flush(dp->dp_spa);
 	txg_fini(dp);
 	dsl_scan_fini(dp);
-	dsl_pool_txg_history_destroy(dp);
 	rrw_destroy(&dp->dp_config_rwlock);
 	mutex_destroy(&dp->dp_lock);
 	taskq_destroy(dp->dp_iput_taskq);
@@ -1182,9 +1041,6 @@ MODULE_PARM_DESC(zfs_write_limit_shift, "log2(fraction of memory) per txg");
 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");
 

module/zfs/txg.c

@@ -31,7 +31,6 @@
 #include <sys/dsl_pool.h>
 #include <sys/dsl_scan.h>
 #include <sys/callb.h>
-#include <sys/spa_impl.h>
 
 /*
  * ZFS Transaction Groups
@@ -351,8 +350,6 @@ txg_rele_to_sync(txg_handle_t *th)
 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;
@@ -373,20 +370,9 @@ txg_quiesce(dsl_pool_t *dp, uint64_t txg)
 	for (c = 0; c < max_ncpus; c++)
 		mutex_exit(&tx->tx_cpu[c].tc_lock);
 
-	/*
-	 * 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);
-
 	/*
 	 * 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);
@@ -394,13 +380,6 @@ txg_quiesce(dsl_pool_t *dp, uint64_t txg)
 			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
@@ -487,8 +466,6 @@ txg_sync_thread(dsl_pool_t *dp)
 
 	start = delta = 0;
 	for (;;) {
-		hrtime_t hrstart;
-		txg_history_t *th;
 		uint64_t timer, timeout;
 		uint64_t txg;
 
@@ -535,17 +512,11 @@ txg_sync_thread(dsl_pool_t *dp)
 		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;
 
@@ -558,23 +529,6 @@ txg_sync_thread(dsl_pool_t *dp)
 		 * 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);
 	}
 }