Update all default taskq settings

Over the years the default values for the taskqs used on Linux have
differed slightly from illumos.  In the vast majority of cases this
was done to avoid creating an obnoxious number of idle threads which
would pollute the process listing.

With the addition of support for dynamic taskqs all multi-threaded
queues should be created as dynamic taskqs.  This allows us to get
the best of both worlds.

* The illumos default values for the I/O pipeline can be restored.
These values are known to work well for most workloads.  The only
exception is the zio write interrupt taskq which is changed to
ZTI_P(12, 8).  At least under Linux more threads has been shown
to improve performance, see commit 7e55f4e.

* Reduces the number of idle threads on the system when it's not
under heavy load.  The maximum number of threads will only be
created when they are required.

* Remove the vdev_file_taskq and rely on the system_taskq instead
which is now dynamic and may have up to 64-threads.  Again this
brings us back inline with upstream.

* Tasks dispatched with taskq_dispatch_ent() are allowed to use
dynamic taskqs.  The Linux taskq implementation supports this.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Closes #3507

diff --git a/include/sys/vdev_file.h b/include/sys/vdev_file.h
index cf38a86afeabae1ec5c3587ed5ac247c41a88f4c..aebcf55cfd9a9fab9cbaf9dbd78923be7ec2f656 100644 (file)
--- a/include/sys/vdev_file.h
+++ b/include/sys/vdev_file.h
@@ -27,8 +27,6 @@
 #ifndef _SYS_VDEV_FILE_H
 #define        _SYS_VDEV_FILE_H
 
-
-
 #include <sys/vdev.h>
 
 #ifdef __cplusplus
@@ -39,9 +37,6 @@ typedef struct vdev_file {
        vnode_t         *vf_vnode;
 } vdev_file_t;
 
-extern void vdev_file_init(void);
-extern void vdev_file_fini(void);
-
 #ifdef __cplusplus
 }
 #endif

diff --git a/lib/libzpool/taskq.c b/lib/libzpool/taskq.c
index c6fa2fff72b6fe350d11df0d4e6d3c4d08c5fe8f..59b4c7c05f7950f42721464aae1fb083e055e9f7 100644 (file)
--- a/lib/libzpool/taskq.c
+++ b/lib/libzpool/taskq.c
@@ -178,7 +178,6 @@ taskq_dispatch_ent(taskq_t *tq, task_func_t func, void *arg, uint_t flags,
     taskq_ent_t *t)
 {
        ASSERT(func != NULL);
-       ASSERT(!(tq->tq_flags & TASKQ_DYNAMIC));
 
        /*
         * Mark it as a prealloc'd task.  This is important

diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index 16d9706729f404661faa850e61780124ac05899f..99fa698722e2d082fd4826d92b5e6061bde128a8 100644 (file)
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -5002,7 +5002,7 @@ arc_init(void)
        bzero(&arc_eviction_hdr, sizeof (arc_buf_hdr_t));
 
        arc_prune_taskq = taskq_create("arc_prune", max_ncpus, minclsyspri,
-           max_ncpus, INT_MAX, TASKQ_PREPOPULATE);
+           max_ncpus, INT_MAX, TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
 
        arc_ksp = kstat_create("zfs", 0, "arcstats", "misc", KSTAT_TYPE_NAMED,
            sizeof (arc_stats) / sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL);

diff --git a/module/zfs/dsl_pool.c b/module/zfs/dsl_pool.c
index 908c44e702a176b531dda03ee67c3655d8d2e4b4..5d804352ddfc418a3854903723e3eac09775ae34 100644 (file)
--- a/module/zfs/dsl_pool.c
+++ b/module/zfs/dsl_pool.c
@@ -171,7 +171,7 @@ dsl_pool_open_impl(spa_t *spa, uint64_t txg)
        cv_init(&dp->dp_spaceavail_cv, NULL, CV_DEFAULT, NULL);
 
        dp->dp_iput_taskq = taskq_create("z_iput", max_ncpus, minclsyspri,
-           max_ncpus * 8, INT_MAX, TASKQ_PREPOPULATE);
+           max_ncpus * 8, INT_MAX, TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
 
        return (dp);
 }

diff --git a/module/zfs/metaslab.c b/module/zfs/metaslab.c
index 3b556b6dbfae17c04a565408de08849d8ee83e6a..d6ee81c859d0f6e4538a3acd9ae82328e22326e7 100644 (file)
--- a/module/zfs/metaslab.c
+++ b/module/zfs/metaslab.c
@@ -492,7 +492,7 @@ metaslab_group_create(metaslab_class_t *mc, vdev_t *vd)
        mg->mg_activation_count = 0;
 
        mg->mg_taskq = taskq_create("metaslab_group_taskq", metaslab_load_pct,
-           minclsyspri, 10, INT_MAX, TASKQ_THREADS_CPU_PCT);
+           minclsyspri, 10, INT_MAX, TASKQ_THREADS_CPU_PCT | TASKQ_DYNAMIC);
 
        return (mg);
 }

diff --git a/module/zfs/spa.c b/module/zfs/spa.c
index ad109a641c4625dd29326f8d5fd625792a32d747..b5e024c3f2911b069b3c1b46bb5e16f13662576c 100644 (file)
--- a/module/zfs/spa.c
+++ b/module/zfs/spa.c
@@ -127,9 +127,9 @@ static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
 const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
        /* ISSUE        ISSUE_HIGH      INTR            INTR_HIGH */
        { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* NULL */
-       { ZTI_N(8),     ZTI_NULL,       ZTI_BATCH,      ZTI_NULL }, /* READ */
-       { ZTI_BATCH,    ZTI_N(5),       ZTI_N(16),      ZTI_N(5) }, /* WRITE */
-       { ZTI_P(4, 8),  ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* FREE */
+       { ZTI_N(8),     ZTI_NULL,       ZTI_P(12, 8),   ZTI_NULL }, /* READ */
+       { ZTI_BATCH,    ZTI_N(5),       ZTI_P(12, 8),   ZTI_N(5) }, /* WRITE */
+       { ZTI_P(12, 8), ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* FREE */
        { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* CLAIM */
        { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* IOCTL */
 };
@@ -844,7 +844,7 @@ spa_taskqs_init(spa_t *spa, zio_type_t t, zio_taskq_type_t q)
        uint_t count = ztip->zti_count;
        spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
        char name[32];
-       uint_t i, flags = 0;
+       uint_t i, flags = TASKQ_DYNAMIC;
        boolean_t batch = B_FALSE;
 
        if (mode == ZTI_MODE_NULL) {

diff --git a/module/zfs/spa_misc.c b/module/zfs/spa_misc.c
index 26b6f1731a85c8fef13c18aaa8a7b4344f3079ec..ad9f9fe2839a98d123e356a89c41cf66de3cc587 100644 (file)
--- a/module/zfs/spa_misc.c
+++ b/module/zfs/spa_misc.c
@@ -1829,7 +1829,6 @@ spa_init(int mode)
        dmu_init();
        zil_init();
        vdev_cache_stat_init();
-       vdev_file_init();
        zfs_prop_init();
        zpool_prop_init();
        zpool_feature_init();
@@ -1844,7 +1843,6 @@ spa_fini(void)
 
        spa_evict_all();
 
-       vdev_file_fini();
        vdev_cache_stat_fini();
        zil_fini();
        dmu_fini();

diff --git a/module/zfs/txg.c b/module/zfs/txg.c
index 9accd48df062dfc58a56cc94f05ba280ded546dc..7681856ea14098d77fe4d1ce6019953566c65a99 100644 (file)
--- a/module/zfs/txg.c
+++ b/module/zfs/txg.c
@@ -445,8 +445,8 @@ txg_dispatch_callbacks(dsl_pool_t *dp, uint64_t txg)
                         * Commit callback taskq hasn't been created yet.
                         */
                        tx->tx_commit_cb_taskq = taskq_create("tx_commit_cb",
-                           100, minclsyspri, max_ncpus, INT_MAX,
-                           TASKQ_THREADS_CPU_PCT | TASKQ_PREPOPULATE);
+                           max_ncpus, minclsyspri, max_ncpus, max_ncpus * 2,
+                           TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
                }
 
                cb_list = kmem_alloc(sizeof (list_t), KM_SLEEP);

diff --git a/module/zfs/vdev_file.c b/module/zfs/vdev_file.c
index 3c3a139931006997db05e06c82241adf46003a49..e61240fdcc5481369331875c9ec730832a64eb72 100644 (file)
--- a/module/zfs/vdev_file.c
+++ b/module/zfs/vdev_file.c
@@ -36,8 +36,6 @@
  * Virtual device vector for files.
  */
 
-static taskq_t *vdev_file_taskq;
-
 static void
 vdev_file_hold(vdev_t *vd)
 {
@@ -200,7 +198,7 @@ vdev_file_io_start(zio_t *zio)
                         * the sync must be dispatched to a different context.
                         */
                        if (spl_fstrans_check()) {
-                               VERIFY3U(taskq_dispatch(vdev_file_taskq,
+                               VERIFY3U(taskq_dispatch(system_taskq,
                                    vdev_file_io_fsync, zio, TQ_SLEEP), !=, 0);
                                return;
                        }
@@ -216,7 +214,7 @@ vdev_file_io_start(zio_t *zio)
                return;
        }
 
-       VERIFY3U(taskq_dispatch(vdev_file_taskq, vdev_file_io_strategy, zio,
+       VERIFY3U(taskq_dispatch(system_taskq, vdev_file_io_strategy, zio,
            TQ_SLEEP), !=, 0);
 }
 
@@ -239,21 +237,6 @@ vdev_ops_t vdev_file_ops = {
        B_TRUE                  /* leaf vdev */
 };
 
-void
-vdev_file_init(void)
-{
-       vdev_file_taskq = taskq_create("vdev_file_taskq", 100, minclsyspri,
-           max_ncpus, INT_MAX, TASKQ_PREPOPULATE | TASKQ_THREADS_CPU_PCT);
-
-       VERIFY(vdev_file_taskq);
-}
-
-void
-vdev_file_fini(void)
-{
-       taskq_destroy(vdev_file_taskq);
-}
-
 /*
  * From userland we access disks just like files.
  */

diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c
index d180b5b5b76f468ba67aa6b71e5f35d094727c11..8646892ea826d0c137cf243247407a2e953f277e 100644 (file)
--- a/module/zfs/zvol.c
+++ b/module/zfs/zvol.c
@@ -1632,7 +1632,7 @@ zvol_init(void)
        mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL);
 
        zvol_taskq = taskq_create(ZVOL_DRIVER, zvol_threads, maxclsyspri,
-           zvol_threads, INT_MAX, TASKQ_PREPOPULATE);
+           zvol_threads * 2, INT_MAX, TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
        if (zvol_taskq == NULL) {
                printk(KERN_INFO "ZFS: taskq_create() failed\n");
                error = -ENOMEM;