Some microoptimizations for da and ada drivers:

 - Replace ordered_tag_count counter with single flag;
 - From da remove outstanding_cmds counter, duplicating pending_ccbs list;
 - From da_softc remove unused links field.

2 files changed, 21 insertions, 41 deletions

diff --git a/sys/cam/ata/ata_da.c b/sys/cam/ata/ata_da.c
index 24cc8f4dd71d..c30be2d81132 100644
--- a/sys/cam/ata/ata_da.c
+++ b/sys/cam/ata/ata_da.c
@@ -80,7 +80,7 @@ typedef enum {
 	ADA_FLAG_CAN_NCQ	= 0x0008,
 	ADA_FLAG_CAN_DMA	= 0x0010,
 	ADA_FLAG_NEED_OTAG	= 0x0020,
-	ADA_FLAG_WENT_IDLE	= 0x0040,
+	ADA_FLAG_WAS_OTAG	= 0x0040,
 	ADA_FLAG_CAN_TRIM	= 0x0080,
 	ADA_FLAG_OPEN		= 0x0100,
 	ADA_FLAG_SCTX_INIT	= 0x0200,
@@ -130,12 +130,12 @@ struct trim_request {
 struct ada_softc {
 	struct	 bio_queue_head bio_queue;
 	struct	 bio_queue_head trim_queue;
+	int	 outstanding_cmds;	/* Number of active commands */
+	int	 refcount;		/* Active xpt_action() calls */
 	ada_state state;
-	ada_flags flags;	
+	ada_flags flags;
 	ada_quirks quirks;
 	int	 sort_io_queue;
-	int	 ordered_tag_count;
-	int	 outstanding_cmds;
 	int	 trim_max_ranges;
 	int	 trim_running;
 	int	 read_ahead;
@@ -153,7 +153,6 @@ struct ada_softc {
 	struct sysctl_oid	*sysctl_tree;
 	struct callout		sendordered_c;
 	struct trim_request	trim_req;
-	int	refcount;
 };
 
 struct ada_quirk_entry {
@@ -1489,7 +1488,7 @@ adastart(struct cam_periph *periph, union ccb *start_ccb)
 		if ((bp->bio_flags & BIO_ORDERED) != 0
 		 || (softc->flags & ADA_FLAG_NEED_OTAG) != 0) {
 			softc->flags &= ~ADA_FLAG_NEED_OTAG;
-			softc->ordered_tag_count++;
+			softc->flags |= ADA_FLAG_WAS_OTAG;
 			tag_code = 0;
 		} else {
 			tag_code = 1;
@@ -1743,7 +1742,7 @@ adadone(struct cam_periph *periph, union ccb *done_ccb)
 		}
 		softc->outstanding_cmds--;
 		if (softc->outstanding_cmds == 0)
-			softc->flags |= ADA_FLAG_WENT_IDLE;
+			softc->flags |= ADA_FLAG_WAS_OTAG;
 		xpt_release_ccb(done_ccb);
 		if (state == ADA_CCB_TRIM) {
 			TAILQ_HEAD(, bio) queue;
@@ -1905,14 +1904,11 @@ adasendorderedtag(void *arg)
 	struct ada_softc *softc = arg;
 
 	if (ada_send_ordered) {
-		if ((softc->ordered_tag_count == 0) 
-		 && ((softc->flags & ADA_FLAG_WENT_IDLE) == 0)) {
-			softc->flags |= ADA_FLAG_NEED_OTAG;
+		if (softc->outstanding_cmds > 0) {
+			if ((softc->flags & ADA_FLAG_WAS_OTAG) == 0)
+				softc->flags |= ADA_FLAG_NEED_OTAG;
+			softc->flags &= ~ADA_FLAG_WAS_OTAG;
 		}
-		if (softc->outstanding_cmds > 0)
-			softc->flags &= ~ADA_FLAG_WENT_IDLE;
-
-		softc->ordered_tag_count = 0;
 	}
 	/* Queue us up again */
 	callout_reset(&softc->sendordered_c,
diff --git a/sys/cam/scsi/scsi_da.c b/sys/cam/scsi/scsi_da.c
index 7c5941d04445..980282d6fee6 100644
--- a/sys/cam/scsi/scsi_da.c
+++ b/sys/cam/scsi/scsi_da.c
@@ -84,7 +84,7 @@ typedef enum {
 	DA_FLAG_PACK_LOCKED	= 0x004,
 	DA_FLAG_PACK_REMOVABLE	= 0x008,
 	DA_FLAG_NEED_OTAG	= 0x020,
-	DA_FLAG_WENT_IDLE	= 0x040,
+	DA_FLAG_WAS_OTAG	= 0x040,
 	DA_FLAG_RETRY_UA	= 0x080,
 	DA_FLAG_OPEN		= 0x100,
 	DA_FLAG_SCTX_INIT	= 0x200,
@@ -198,19 +198,17 @@ struct da_softc {
 	struct	 bio_queue_head bio_queue;
 	struct	 bio_queue_head delete_queue;
 	struct	 bio_queue_head delete_run_queue;
-	SLIST_ENTRY(da_softc) links;
 	LIST_HEAD(, ccb_hdr) pending_ccbs;
+	int	 tur;			/* TEST UNIT READY should be sent */
+	int	 refcount;		/* Active xpt_action() calls */
 	da_state state;
 	da_flags flags;	
 	da_quirks quirks;
 	int	 sort_io_queue;
 	int	 minimum_cmd_size;
 	int	 error_inject;
-	int	 ordered_tag_count;
-	int	 outstanding_cmds;
 	int	 trim_max_ranges;
 	int	 delete_running;
-	int	 tur;
 	int	 delete_available;	/* Delete methods possibly available */
 	uint32_t		unmap_max_ranges;
 	uint32_t		unmap_max_lba;
@@ -228,7 +226,6 @@ struct da_softc {
 	uint8_t	 unmap_buf[UNMAP_BUF_SIZE];
 	struct scsi_read_capacity_data_long rcaplong;
 	struct callout		mediapoll_c;
-	int	refcount;
 };
 
 #define dadeleteflag(softc, delete_method, enable)			\
@@ -2244,7 +2241,7 @@ skipstate:
 		if ((bp->bio_flags & BIO_ORDERED) != 0 ||
 		    (softc->flags & DA_FLAG_NEED_OTAG) != 0) {
 			softc->flags &= ~DA_FLAG_NEED_OTAG;
-			softc->ordered_tag_count++;
+			softc->flags |= DA_FLAG_WAS_OTAG;
 			tag_code = MSG_ORDERED_Q_TAG;
 		} else {
 			tag_code = MSG_SIMPLE_Q_TAG;
@@ -2297,13 +2294,8 @@ skipstate:
 		start_ccb->ccb_h.flags |= CAM_UNLOCKED;
 
 out:
-		/*
-		 * Block out any asynchronous callbacks
-		 * while we touch the pending ccb list.
-		 */
 		LIST_INSERT_HEAD(&softc->pending_ccbs,
 				 &start_ccb->ccb_h, periph_links.le);
-		softc->outstanding_cmds++;
 
 		/* We expect a unit attention from this device */
 		if ((softc->flags & DA_FLAG_RETRY_UA) != 0) {
@@ -2969,14 +2961,9 @@ dadone(struct cam_periph *periph, union ccb *done_ccb)
 			}
 		}
 
-		/*
-		 * Block out any asynchronous callbacks
-		 * while we touch the pending ccb list.
-		 */
 		LIST_REMOVE(&done_ccb->ccb_h, periph_links.le);
-		softc->outstanding_cmds--;
-		if (softc->outstanding_cmds == 0)
-			softc->flags |= DA_FLAG_WENT_IDLE;
+		if (LIST_EMPTY(&softc->pending_ccbs))
+			softc->flags |= DA_FLAG_WAS_OTAG;
 
 		xpt_release_ccb(done_ccb);
 		if (state == DA_CCB_DELETE) {
@@ -3583,7 +3570,7 @@ damediapoll(void *arg)
 	struct cam_periph *periph = arg;
 	struct da_softc *softc = periph->softc;
 
-	if (!softc->tur && softc->outstanding_cmds == 0) {
+	if (!softc->tur && LIST_EMPTY(&softc->pending_ccbs)) {
 		if (cam_periph_acquire(periph) == CAM_REQ_CMP) {
 			softc->tur = 1;
 			daschedule(periph);
@@ -3755,14 +3742,11 @@ dasendorderedtag(void *arg)
 	struct da_softc *softc = arg;
 
 	if (da_send_ordered) {
-		if ((softc->ordered_tag_count == 0) 
-		 && ((softc->flags & DA_FLAG_WENT_IDLE) == 0)) {
-			softc->flags |= DA_FLAG_NEED_OTAG;
+		if (!LIST_EMPTY(&softc->pending_ccbs)) {
+			if ((softc->flags & DA_FLAG_WAS_OTAG) == 0)
+				softc->flags |= DA_FLAG_NEED_OTAG;
+			softc->flags &= ~DA_FLAG_WAS_OTAG;
 		}
-		if (softc->outstanding_cmds > 0)
-			softc->flags &= ~DA_FLAG_WENT_IDLE;
-
-		softc->ordered_tag_count = 0;
 	}
 	/* Queue us up again */
 	callout_reset(&softc->sendordered_c,