Make more taskq parameters writable

There is no reason for these module parameters to be read-only.
Being modified they just apply on next pool import/creation, that
is useful for testing different values.

Reviewed-by: Rich Ercolani <rincebrain@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Closes #16118

man/man4/zfs.4

@@ -2324,15 +2324,16 @@ Prioritize requeued I/O.
 .
 .It Sy zio_taskq_batch_pct Ns = Ns Sy 80 Ns % Pq uint
 Percentage of online CPUs which will run a worker thread for I/O.
-These workers are responsible for I/O work such as compression and
-checksum calculations.
+These workers are responsible for I/O work such as compression, encryption,
+checksum and parity calculations.
 Fractional number of CPUs will be rounded down.
 .Pp
 The default value of
 .Sy 80%
 was chosen to avoid using all CPUs which can result in
 latency issues and inconsistent application performance,
 especially when slower compression and/or checksumming is enabled.
+Set value only applies to pools imported/created after that.
 .
 .It Sy zio_taskq_batch_tpq Ns = Ns Sy 0 Pq uint
 Number of worker threads per taskq.
@@ -2342,16 +2343,19 @@ while higher reduces lock contention.
 If
 .Sy 0 ,
 generate a system-dependent value close to 6 threads per taskq.
+Set value only applies to pools imported/created after that.
 .
 .It Sy zio_taskq_read Ns = Ns Sy fixed,1,8 null scale null Pq charp
 Set the queue and thread configuration for the IO read queues.
 This is an advanced debugging parameter.
 Don't change this unless you understand what it does.
+Set values only apply to pools imported/created after that.
 .
 .It Sy zio_taskq_write Ns = Ns Sy batch fixed,1,5 scale fixed,1,5 Pq charp
 Set the queue and thread configuration for the IO write queues.
 This is an advanced debugging parameter.
 Don't change this unless you understand what it does.
+Set values only apply to pools imported/created after that.
 .
 .It Sy zvol_inhibit_dev Ns = Ns Sy 0 Ns | Ns 1 Pq uint
 Do not create zvol device nodes.

module/zfs/spa.c

@@ -10561,10 +10561,10 @@ ZFS_MODULE_PARAM(zfs_spa, spa_, load_verify_data, INT, ZMOD_RW,
 ZFS_MODULE_PARAM(zfs_spa, spa_, load_print_vdev_tree, INT, ZMOD_RW,
 	"Print vdev tree to zfs_dbgmsg during pool import");
 
-ZFS_MODULE_PARAM(zfs_zio, zio_, taskq_batch_pct, UINT, ZMOD_RD,
+ZFS_MODULE_PARAM(zfs_zio, zio_, taskq_batch_pct, UINT, ZMOD_RW,
 	"Percentage of CPUs to run an IO worker thread");
 
-ZFS_MODULE_PARAM(zfs_zio, zio_, taskq_batch_tpq, UINT, ZMOD_RD,
+ZFS_MODULE_PARAM(zfs_zio, zio_, taskq_batch_tpq, UINT, ZMOD_RW,
 	"Number of threads per IO worker taskqueue");
 
 /* BEGIN CSTYLED */
@@ -10595,10 +10595,10 @@ ZFS_MODULE_PARAM(zfs_livelist_condense, zfs_livelist_condense_, new_alloc, INT,
 
 #ifdef _KERNEL
 ZFS_MODULE_VIRTUAL_PARAM_CALL(zfs_zio, zio_, taskq_read,
-	spa_taskq_read_param_set, spa_taskq_read_param_get, ZMOD_RD,
+	spa_taskq_read_param_set, spa_taskq_read_param_get, ZMOD_RW,
 	"Configure IO queues for read IO");
 ZFS_MODULE_VIRTUAL_PARAM_CALL(zfs_zio, zio_, taskq_write,
-	spa_taskq_write_param_set, spa_taskq_write_param_get, ZMOD_RD,
+	spa_taskq_write_param_set, spa_taskq_write_param_get, ZMOD_RW,
 	"Configure IO queues for write IO");
 #endif
 /* END CSTYLED */