Update arc_summary and arcstat outputs

Recent ARC commits added new statistic counters, such as iohits,
uncached state, etc.  Represent those.  Also some of previously
reported numbers were confusing or even made no sense.  Cleanup
and restructure existing reports.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by:  Alexander Motin <mav@FreeBSD.org>
Sponsored by:   iXsystems, Inc.
Issue #14115 
Issue #14123
Issue #14243 
Closes #14320

man/man1/arcstat.1

@@ -12,7 +12,7 @@
 .\" Copyright (c) 2015 by Delphix. All rights reserved.
 .\" Copyright (c) 2020 by AJ Jordan. All rights reserved.
 .\"
-.Dd May 26, 2021
+.Dd December 23, 2022
 .Dt ARCSTAT 1
 .Os
 .
@@ -35,33 +35,83 @@ prints various ZFS ARC and L2ARC statistics in vmstat-like fashion:
 .It Sy c
 ARC target size
 .It Sy dh%
-Demand data hit percentage
+Demand hit percentage
+.It Sy di%
+Demand I/O hit percentage
 .It Sy dm%
+Demand miss percentage
+.It Sy ddh%
+Demand data hit percentage
+.It Sy ddi%
+Demand data I/O hit percentage
+.It Sy ddm%
 Demand data miss percentage
+.It Sy dmh%
+Demand metadata hit percentage
+.It Sy dmi%
+Demand metadata I/O hit percentage
+.It Sy dmm%
+Demand metadata miss percentage
 .It Sy mfu
 MFU list hits per second
 .It Sy mh%
 Metadata hit percentage
+.It Sy mi%
+Metadata I/O hit percentage
 .It Sy mm%
 Metadata miss percentage
 .It Sy mru
 MRU list hits per second
 .It Sy ph%
 Prefetch hits percentage
+.It Sy pi%
+Prefetch I/O hits percentage
 .It Sy pm%
 Prefetch miss percentage
+.It Sy pdh%
+Prefetch data hits percentage
+.It Sy pdi%
+Prefetch data I/O hits percentage
+.It Sy pdm%
+Prefetch data miss percentage
+.It Sy pmh%
+Prefetch metadata hits percentage
+.It Sy pmi%
+Prefetch metadata I/O hits percentage
+.It Sy pmm%
+Prefetch metadata miss percentage
 .It Sy dhit
-Demand data hits per second
+Demand hits per second
+.It Sy dioh
+Demand I/O hits per second
 .It Sy dmis
+Demand misses per second
+.It Sy ddhit
+Demand data hits per second
+.It Sy ddioh
+Demand data I/O hits per second
+.It Sy ddmis
 Demand data misses per second
+.It Sy dmhit
+Demand metadata hits per second
+.It Sy dmioh
+Demand metadata I/O hits per second
+.It Sy dmmis
+Demand metadata misses per second
 .It Sy hit%
 ARC hit percentage
 .It Sy hits
-ARC reads per second
+ARC hits per second
+.It Sy ioh%
+ARC I/O hits percentage
+.It Sy iohs
+ARC I/O hits per second
 .It Sy mfug
 MFU ghost list hits per second
 .It Sy mhit
 Metadata hits per second
+.It Sy mioh
+Metadata I/O hits per second
 .It Sy miss
 ARC misses per second
 .It Sy mmis
@@ -70,8 +120,22 @@ Metadata misses per second
 MRU ghost list hits per second
 .It Sy phit
 Prefetch hits per second
+.It Sy pioh
+Prefetch I/O hits per second
 .It Sy pmis
 Prefetch misses per second
+.It Sy pdhit
+Prefetch data hits per second
+.It Sy pdioh
+Prefetch data I/O hits per second
+.It Sy pdmis
+Prefetch data misses per second
+.It Sy pmhit
+Prefetch metadata hits per second
+.It Sy pmioh
+Prefetch metadata I/O hits per second
+.It Sy pmmis
+Prefetch metadata misses per second
 .It Sy read
 Total ARC accesses per second
 .It Sy time
@@ -81,8 +145,14 @@ ARC size
 .It Sy arcsz
 Alias for
 .Sy size
+.It Sy unc
+Uncached list hits per second
 .It Sy dread
+Demand accesses per second
+.It Sy ddread
 Demand data accesses per second
+.It Sy dmread
+Demand metadata accesses per second
 .It Sy eskip
 evict_skip per second
 .It Sy miss%
@@ -91,6 +161,10 @@ ARC miss percentage
 Metadata accesses per second
 .It Sy pread
 Prefetch accesses per second
+.It Sy pdread
+Prefetch data accesses per second
+.It Sy pmread
+Prefetch metadata accesses per second
 .It Sy l2hit%
 L2ARC access hit percentage
 .It Sy l2hits