Remove pool io kstats (#12212)

This mostly reverts "3537 want pool io kstats" commit of 8 years ago.

From one side this code using pool-wide locks became pretty bad for
performance, creating significant lock contention in I/O pipeline.
From another, there are more efficient ways now to obtain detailed
statistics, while this statistics is illumos-specific and much less
usable on Linux and FreeBSD, reported only via procfs/sysctls.

This commit does not remove KSTAT_TYPE_IO implementation, that may
be removed later together with already unused KSTAT_TYPE_INTR and
KSTAT_TYPE_TIMER.

Reviewed-by: Matthew Ahrens <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Alexander Motin <[email protected]>
Sponsored-By: iXsystems, Inc.
Closes #12212 

2 files changed, 0 insertions, 128 deletions

diff --git a/module/os/freebsd/spl/spl_kstat.c b/module/os/freebsd/spl/spl_kstat.c
index e591921ac..059ada235 100644
--- a/module/os/freebsd/spl/spl_kstat.c
+++ b/module/os/freebsd/spl/spl_kstat.c
@@ -508,65 +508,3 @@ kstat_delete(kstat_t *ksp)
 		kmem_free(ksp->ks_data, ksp->ks_data_size);
 	free(ksp, M_KSTAT);
 }
-
-void
-kstat_waitq_enter(kstat_io_t *kiop)
-{
-	hrtime_t new, delta;
-	ulong_t wcnt;
-
-	new = gethrtime();
-	delta = new - kiop->wlastupdate;
-	kiop->wlastupdate = new;
-	wcnt = kiop->wcnt++;
-	if (wcnt != 0) {
-		kiop->wlentime += delta * wcnt;
-		kiop->wtime += delta;
-	}
-}
-
-void
-kstat_waitq_exit(kstat_io_t *kiop)
-{
-	hrtime_t new, delta;
-	ulong_t wcnt;
-
-	new = gethrtime();
-	delta = new - kiop->wlastupdate;
-	kiop->wlastupdate = new;
-	wcnt = kiop->wcnt--;
-	ASSERT3S(wcnt, >, 0);
-	kiop->wlentime += delta * wcnt;
-	kiop->wtime += delta;
-}
-
-void
-kstat_runq_enter(kstat_io_t *kiop)
-{
-	hrtime_t new, delta;
-	ulong_t rcnt;
-
-	new = gethrtime();
-	delta = new - kiop->rlastupdate;
-	kiop->rlastupdate = new;
-	rcnt = kiop->rcnt++;
-	if (rcnt != 0) {
-		kiop->rlentime += delta * rcnt;
-		kiop->rtime += delta;
-	}
-}
-
-void
-kstat_runq_exit(kstat_io_t *kiop)
-{
-	hrtime_t new, delta;
-	ulong_t rcnt;
-
-	new = gethrtime();
-	delta = new - kiop->rlastupdate;
-	kiop->rlastupdate = new;
-	rcnt = kiop->rcnt--;
-	ASSERT3S(rcnt, >, 0);
-	kiop->rlentime += delta * rcnt;
-	kiop->rtime += delta;
-}
diff --git a/module/os/linux/spl/spl-kstat.c b/module/os/linux/spl/spl-kstat.c
index c7f1aadf7..0c4670832 100644
--- a/module/os/linux/spl/spl-kstat.c
+++ b/module/os/linux/spl/spl-kstat.c
@@ -50,72 +50,6 @@ kstat_resize_raw(kstat_t *ksp)
 	return (0);
 }
 
-void
-kstat_waitq_enter(kstat_io_t *kiop)
-{
-	hrtime_t new, delta;
-	ulong_t wcnt;
-
-	new = gethrtime();
-	delta = new - kiop->wlastupdate;
-	kiop->wlastupdate = new;
-	wcnt = kiop->wcnt++;
-	if (wcnt != 0) {
-		kiop->wlentime += delta * wcnt;
-		kiop->wtime += delta;
-	}
-}
-EXPORT_SYMBOL(kstat_waitq_enter);
-
-void
-kstat_waitq_exit(kstat_io_t *kiop)
-{
-	hrtime_t new, delta;
-	ulong_t wcnt;
-
-	new = gethrtime();
-	delta = new - kiop->wlastupdate;
-	kiop->wlastupdate = new;
-	wcnt = kiop->wcnt--;
-	ASSERT((int)wcnt > 0);
-	kiop->wlentime += delta * wcnt;
-	kiop->wtime += delta;
-}
-EXPORT_SYMBOL(kstat_waitq_exit);
-
-void
-kstat_runq_enter(kstat_io_t *kiop)
-{
-	hrtime_t new, delta;
-	ulong_t rcnt;
-
-	new = gethrtime();
-	delta = new - kiop->rlastupdate;
-	kiop->rlastupdate = new;
-	rcnt = kiop->rcnt++;
-	if (rcnt != 0) {
-		kiop->rlentime += delta * rcnt;
-		kiop->rtime += delta;
-	}
-}
-EXPORT_SYMBOL(kstat_runq_enter);
-
-void
-kstat_runq_exit(kstat_io_t *kiop)
-{
-	hrtime_t new, delta;
-	ulong_t rcnt;
-
-	new = gethrtime();
-	delta = new - kiop->rlastupdate;
-	kiop->rlastupdate = new;
-	rcnt = kiop->rcnt--;
-	ASSERT((int)rcnt > 0);
-	kiop->rlentime += delta * rcnt;
-	kiop->rtime += delta;
-}
-EXPORT_SYMBOL(kstat_runq_exit);
-
 static int
 kstat_seq_show_headers(struct seq_file *f)
 {