scsi: lpfc: Make ktime sampling more accurate

Need to make ktime samples more accurate

If ktime is turned on in the middle of an IO, the max calculation could
be misleading. Base sampling on the start time of the IO as opposed to
ktime_on.

Make ISR ktime timestamps be from when CQE is read instead of EQE.
Added additional sanity checks when deciding whether to accept an IO
sample or not.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 20 insertions, 14 deletions

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 8026a327820f..abd528266fdc 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -13064,13 +13064,20 @@ lpfc_sli4_sp_handle_eqe(struct lpfc_hba *phba, struct lpfc_eqe *eqe,
 		break;
 	case LPFC_WCQ:
 		while ((cqe = lpfc_sli4_cq_get(cq))) {
-			if ((cq->subtype == LPFC_FCP) ||
-			    (cq->subtype == LPFC_NVME))
+			if (cq->subtype == LPFC_FCP ||
+			    cq->subtype == LPFC_NVME) {
+#ifdef CONFIG_SCSI_LPFC_DEBUG_FS
+				if (phba->ktime_on)
+					cq->isr_timestamp = ktime_get_ns();
+				else
+					cq->isr_timestamp = 0;
+#endif
 				workposted |= lpfc_sli4_fp_handle_cqe(phba, cq,
 								       cqe);
-			else
+			} else {
 				workposted |= lpfc_sli4_sp_handle_cqe(phba, cq,
 								      cqe);
+			}
 			if (!(++ecount % cq->entry_repost))
 				break;
 		}
@@ -13155,11 +13162,9 @@ lpfc_sli4_fp_handle_fcp_wcqe(struct lpfc_hba *phba, struct lpfc_queue *cq,
 				bf_get(lpfc_wcqe_c_request_tag, wcqe));
 		return;
 	}
-
-	if (cq->assoc_qp)
-		cmdiocbq->isr_timestamp =
-			cq->assoc_qp->isr_timestamp;
-
+#ifdef CONFIG_SCSI_LPFC_DEBUG_FS
+	cmdiocbq->isr_timestamp = cq->isr_timestamp;
+#endif
 	if (cmdiocbq->iocb_cmpl == NULL) {
 		if (cmdiocbq->wqe_cmpl) {
 			if (cmdiocbq->iocb_flag & LPFC_DRIVER_ABORTED) {
@@ -13304,7 +13309,7 @@ lpfc_sli4_nvmet_handle_rcqe(struct lpfc_hba *phba, struct lpfc_queue *cq,
 			dma_buf->bytes_recv = bf_get(lpfc_rcqe_length,  rcqe);
 			lpfc_nvmet_unsol_fcp_event(
 				phba, idx, dma_buf,
-				cq->assoc_qp->isr_timestamp);
+				cq->isr_timestamp);
 			return false;
 		}
 drop:
@@ -13479,6 +13484,12 @@ process_cq:
 
 	/* Process all the entries to the CQ */
 	while ((cqe = lpfc_sli4_cq_get(cq))) {
+#ifdef CONFIG_SCSI_LPFC_DEBUG_FS
+		if (phba->ktime_on)
+			cq->isr_timestamp = ktime_get_ns();
+		else
+			cq->isr_timestamp = 0;
+#endif
 		workposted |= lpfc_sli4_fp_handle_cqe(phba, cq, cqe);
 		if (!(++ecount % cq->entry_repost))
 			break;
@@ -13741,11 +13752,6 @@ lpfc_sli4_hba_intr_handler(int irq, void *dev_id)
 	if (unlikely(!fpeq))
 		return IRQ_NONE;
 
-#ifdef CONFIG_SCSI_LPFC_DEBUG_FS
-	if (phba->ktime_on)
-		fpeq->isr_timestamp = ktime_get_ns();
-#endif
-
 	if (lpfc_fcp_look_ahead) {
 		if (atomic_dec_and_test(&hba_eq_hdl->hba_eq_in_use))
 			lpfc_sli4_eq_clr_intr(fpeq);