Add request size histograms (-r) to zpool iostat, minor man page fix

Add -r option to "zpool iostat" to print request size histograms for the leaf
ZIOs. This includes histograms of individual ZIOs ("ind") and aggregate ZIOs
("agg"). These stats can be useful for seeing how well the ZFS IO aggregator
is working.

$ zpool iostat -r
mypool        sync_read    sync_write    async_read    async_write      scrub
req_size      ind    agg    ind    agg    ind    agg    ind    agg    ind    agg
----------  -----  -----  -----  -----  -----  -----  -----  -----  -----  -----
512             0      0      0      0      0      0    530      0      0      0
1K              0      0    260      0      0      0    116    246      0      0
2K              0      0      0      0      0      0      0    431      0      0
4K              0      0      0      0      0      0      3    107      0      0
8K             15      0     35      0      0      0      0      6      0      0
16K             0      0      0      0      0      0      0     39      0      0
32K             0      0      0      0      0      0      0      0      0      0
64K            20      0     40      0      0      0      0      0      0      0
128K            0      0     20      0      0      0      0      0      0      0
256K            0      0      0      0      0      0      0      0      0      0
512K            0      0      0      0      0      0      0      0      0      0
1M              0      0      0      0      0      0      0      0      0      0
2M              0      0      0      0      0      0      0      0      0      0
4M              0      0      0      0      0      0    155     19      0      0
8M              0      0      0      0      0      0      0    811      0      0
16M             0      0      0      0      0      0      0     68      0      0
--------------------------------------------------------------------------------

Also rename the stray "-G" in the man page to be "-w" for latency histograms.

Signed-off-by: Tony Hutter <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Signed-off-by: Tim Chase <[email protected]>
Closes #4659

1 files changed, 30 insertions, 7 deletions

diff --git a/include/sys/fs/zfs.h b/include/sys/fs/zfs.h
index 65dba125c..9de50e9a2 100644
--- a/include/sys/fs/zfs.h
+++ b/include/sys/fs/zfs.h
@@ -558,7 +558,17 @@ typedef struct zpool_rewind_policy {
 #define	ZPOOL_CONFIG_VDEV_ASYNC_W_LAT_HISTO	"vdev_async_w_lat_histo"
 #define	ZPOOL_CONFIG_VDEV_SCRUB_LAT_HISTO	"vdev_scrub_histo"
 
-
+/* Request size histograms */
+#define	ZPOOL_CONFIG_VDEV_SYNC_IND_R_HISTO	"vdev_sync_ind_r_histo"
+#define	ZPOOL_CONFIG_VDEV_SYNC_IND_W_HISTO	"vdev_sync_ind_w_histo"
+#define	ZPOOL_CONFIG_VDEV_ASYNC_IND_R_HISTO	"vdev_async_ind_r_histo"
+#define	ZPOOL_CONFIG_VDEV_ASYNC_IND_W_HISTO	"vdev_async_ind_w_histo"
+#define	ZPOOL_CONFIG_VDEV_IND_SCRUB_HISTO	"vdev_ind_scrub_histo"
+#define	ZPOOL_CONFIG_VDEV_SYNC_AGG_R_HISTO	"vdev_sync_agg_r_histo"
+#define	ZPOOL_CONFIG_VDEV_SYNC_AGG_W_HISTO	"vdev_sync_agg_w_histo"
+#define	ZPOOL_CONFIG_VDEV_ASYNC_AGG_R_HISTO	"vdev_async_agg_r_histo"
+#define	ZPOOL_CONFIG_VDEV_ASYNC_AGG_W_HISTO	"vdev_async_agg_w_histo"
+#define	ZPOOL_CONFIG_VDEV_AGG_SCRUB_HISTO	"vdev_agg_scrub_histo"
 
 #define	ZPOOL_CONFIG_WHOLE_DISK		"whole_disk"
 #define	ZPOOL_CONFIG_ERRCOUNT		"error_count"
@@ -824,20 +834,33 @@ typedef struct vdev_stat_ex {
 	 * 2^37 nanoseconds = 134s. Timeouts will probably start kicking in
 	 * before this.
 	 */
-#define	VDEV_HISTO_BUCKETS 37
+#define	VDEV_L_HISTO_BUCKETS 37		/* Latency histo buckets */
+#define	VDEV_RQ_HISTO_BUCKETS 25	/* Request size histo buckets */
+
 
 	/* Amount of time in ZIO queue (ns) */
 	uint64_t vsx_queue_histo[ZIO_PRIORITY_NUM_QUEUEABLE]
-	    [VDEV_HISTO_BUCKETS];
+	    [VDEV_L_HISTO_BUCKETS];
 
 	/* Total ZIO latency (ns).  Includes queuing and disk access time */
-	uint64_t vsx_total_histo[ZIO_TYPES][VDEV_HISTO_BUCKETS];
+	uint64_t vsx_total_histo[ZIO_TYPES][VDEV_L_HISTO_BUCKETS];
 
 	/* Amount of time to read/write the disk (ns) */
-	uint64_t vsx_disk_histo[ZIO_TYPES][VDEV_HISTO_BUCKETS];
+	uint64_t vsx_disk_histo[ZIO_TYPES][VDEV_L_HISTO_BUCKETS];
+
+	/* "lookup the bucket for a value" histogram macros */
+#define	HISTO(val, buckets) (val != 0 ? MIN(highbit64(val) - 1, \
+	    buckets - 1) : 0)
+#define	L_HISTO(a) HISTO(a, VDEV_L_HISTO_BUCKETS)
+#define	RQ_HISTO(a) HISTO(a, VDEV_RQ_HISTO_BUCKETS)
+
+	/* Physical IO histogram */
+	uint64_t vsx_ind_histo[ZIO_PRIORITY_NUM_QUEUEABLE]
+	    [VDEV_RQ_HISTO_BUCKETS];
 
-	/* "lookup the bucket for a value" macro */
-#define	HISTO(a) (a != 0 ? MIN(highbit64(a) - 1, VDEV_HISTO_BUCKETS - 1) : 0)
+	/* Delegated (aggregated) physical IO histogram */
+	uint64_t vsx_agg_histo[ZIO_PRIORITY_NUM_QUEUEABLE]
+	    [VDEV_RQ_HISTO_BUCKETS];
 
 } vdev_stat_ex_t;