Make spa_stats.c tunables visible on FreeBSD

Use ZFS_MODULE_PARAM for cross-platform tunables in spa_stats.c, and
add update tunables.cfg in tests for the newly supported ones.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10858

Author: Ryan Moeller

module/zfs/spa_stats.c

@@ -1028,22 +1028,16 @@ spa_stats_destroy(spa_t *spa)
 	spa_mmp_history_destroy(spa);
 }
 
-#if defined(_KERNEL)
-/* CSTYLED */
-module_param(zfs_read_history, int, 0644);
-MODULE_PARM_DESC(zfs_read_history,
-	"Historical statistics for the last N reads");
-
-module_param(zfs_read_history_hits, int, 0644);
-MODULE_PARM_DESC(zfs_read_history_hits,
-	"Include cache hits in read history");
-
-module_param(zfs_txg_history, int, 0644);
-MODULE_PARM_DESC(zfs_txg_history,
-	"Historical statistics for the last N txgs");
-
-module_param(zfs_multihost_history, int, 0644);
-MODULE_PARM_DESC(zfs_multihost_history,
-	"Historical statistics for last N multihost writes");
+/* BEGIN CSTYLED */
+ZFS_MODULE_PARAM(zfs, zfs_, read_history, INT, ZMOD_RW,
+    "Historical statistics for the last N reads");
+
+ZFS_MODULE_PARAM(zfs, zfs_, read_history_hits, INT, ZMOD_RW,
+    "Include cache hits in read history");
+
+ZFS_MODULE_PARAM(zfs_txg, zfs_txg_, history, INT, ZMOD_RW,
+    "Historical statistics for the last N txgs");
+
+ZFS_MODULE_PARAM(zfs_multihost, zfs_multihost_, history, INT, ZMOD_RW,
+    "Historical statistics for last N multihost writes");
 /* END CSTYLED */
-#endif

tests/zfs-tests/include/tunables.cfg

@@ -54,7 +54,7 @@ MAX_MISSING_TVDS		max_missing_tvds		zfs_max_missing_tvds
 METASLAB_DEBUG_LOAD		metaslab.debug_load		metaslab_debug_load
 METASLAB_FORCE_GANGING		metaslab.force_ganging		metaslab_force_ganging
 MULTIHOST_FAIL_INTERVALS	multihost.fail_intervals	zfs_multihost_fail_intervals
-MULTIHOST_HISTORY		UNSUPPORTED			zfs_multihost_history
+MULTIHOST_HISTORY		multihost.history		zfs_multihost_history
 MULTIHOST_IMPORT_INTERVALS	multihost.import_intervals	zfs_multihost_import_intervals
 MULTIHOST_INTERVAL		multihost.interval		zfs_multihost_interval
 OVERRIDE_ESTIMATE_RECORDSIZE	send.override_estimate_recordsize	zfs_override_estimate_recordsize
@@ -73,7 +73,7 @@ SPA_LOAD_VERIFY_METADATA	spa.load_verify_metadata	spa_load_verify_metadata
 TRIM_EXTENT_BYTES_MIN		trim.extent_bytes_min		zfs_trim_extent_bytes_min
 TRIM_METASLAB_SKIP		trim.metaslab_skip		zfs_trim_metaslab_skip
 TRIM_TXG_BATCH			trim.txg_batch			zfs_trim_txg_batch
-TXG_HISTORY			UNSUPPORTED			zfs_txg_history
+TXG_HISTORY			txg.history			zfs_txg_history
 TXG_TIMEOUT			txg.timeout			zfs_txg_timeout
 UNLINK_SUSPEND_PROGRESS		UNSUPPORTED			zfs_unlink_suspend_progress
 VDEV_MIN_MS_COUNT		vdev.min_ms_count		zfs_vdev_min_ms_count