From dcc9770fc0033bd8bb6639ee7b007b3f3f968c51 Mon Sep 17 00:00:00 2001
From: root <root@rhel-storage-100.fast.eng.rdu2.dc.redhat.com>
Date: Fri, 11 Apr 2025 04:29:16 -0400
Subject: [PATCH] nvme-core: print nvme_scan_ns_list exec time

---
 drivers/nvme/host/core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 313e3ba32..eca08f165 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -23,6 +23,7 @@
 #include <linux/pm_qos.h>
 #include <linux/ratelimit.h>
 #include <linux/unaligned.h>
+#include <linux/ktime.h>
 
 #include "nvme.h"
 #include "fabrics.h"
@@ -4242,11 +4243,14 @@ static int nvme_scan_ns_list(struct nvme_ctrl *ctrl)
 	int ret = 0, i;
 	ASYNC_DOMAIN(domain);
 	struct async_scan_task *task;
+	ktime_t start, end;
+	s64 elapsed_ms;
 
 	ns_list = kzalloc(NVME_IDENTIFY_DATA_SIZE, GFP_KERNEL);
 	if (!ns_list)
 		return -ENOMEM;
 
+	start = ktime_get();
 	for (;;) {
 		struct nvme_command cmd = {
 			.identify.opcode	= nvme_admin_identify,
@@ -4287,6 +4291,9 @@ static int nvme_scan_ns_list(struct nvme_ctrl *ctrl)
 	async_synchronize_full_domain(&domain);
 	kfree(ns_list);
 	WARN_ON_ONCE(!list_empty(&ctrl->scan_list));
+	end = ktime_get();
+	elapsed_ms = ktime_to_ms(ktime_sub(end, start));
+	printk("Elapsed time: %lld ms\n", elapsed_ms);
 	return ret;
 }
 
-- 
2.43.5