Use boot_ncpus in place of max_ncpus in taskq_create

Due to hotplug support or BIOS bugs sometimes max_ncpus can be
an absurdly high value. I have a system with 32 cores/threads
but reports max_ncpus == 440. This many threads potentially
cripples the system during arc_prune floods for example.

boot_ncpus is the number of working CPUs when called so use
that instead.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: DHE <git@dehacked.net>
Closes #10282

diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index a6b739ec377aeada5a002ed88e4db38fae9eea38..4f2207ae7831f0e87a5cbf4b0366c87cd29cc3c4 100644 (file)
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -7348,8 +7348,8 @@ arc_init(void)
            offsetof(arc_prune_t, p_node));
        mutex_init(&arc_prune_mtx, NULL, MUTEX_DEFAULT, NULL);
 
-       arc_prune_taskq = taskq_create("arc_prune", max_ncpus, defclsyspri,
-           max_ncpus, INT_MAX, TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
+       arc_prune_taskq = taskq_create("arc_prune", boot_ncpus, defclsyspri,
+           boot_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 fa2c7d695f4efc15b5a16c3f58b8acd5a0235eb7..4dd86a9fe481509e5589f842a9c14cb3710fbe2e 100644 (file)
--- a/module/zfs/dsl_pool.c
+++ b/module/zfs/dsl_pool.c
@@ -220,10 +220,10 @@ dsl_pool_open_impl(spa_t *spa, uint64_t txg)
        mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL);
        cv_init(&dp->dp_spaceavail_cv, NULL, CV_DEFAULT, NULL);
 
-       dp->dp_zrele_taskq = taskq_create("z_zrele", max_ncpus, defclsyspri,
-           max_ncpus * 8, INT_MAX, TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
+       dp->dp_zrele_taskq = taskq_create("z_zrele", boot_ncpus, defclsyspri,
+           boot_ncpus * 8, INT_MAX, TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
        dp->dp_unlinked_drain_taskq = taskq_create("z_unlinked_drain",
-           max_ncpus, defclsyspri, max_ncpus, INT_MAX,
+           boot_ncpus, defclsyspri, boot_ncpus, INT_MAX,
            TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
 
        return (dp);

diff --git a/module/zfs/txg.c b/module/zfs/txg.c
index 2284234feb9003413687be5decff78ad5b54a47d..a5f2b041737b756d07eada81dba566bbba24d0e6 100644 (file)
--- a/module/zfs/txg.c
+++ b/module/zfs/txg.c
@@ -453,7 +453,7 @@ 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",
-                           max_ncpus, defclsyspri, max_ncpus, max_ncpus * 2,
+                           boot_ncpus, defclsyspri, boot_ncpus, boot_ncpus * 2,
                            TASKQ_PREPOPULATE | TASKQ_DYNAMIC);
                }