[PATCH v3 3/3] mm: hugetlb: log time needed to allocate hugepages

[Thomas Prescher via B4 Relay <devnull+thomas.prescher.cyberus-technology.de@kernel.org>]

From: Thomas Prescher <thomas.prescher@cyberus-technology.de>

Having this information allows users to easily tune
the hugepages_node_threads parameter.

Signed-off-by: Thomas Prescher <thomas.prescher@cyberus-technology.de>
---
 mm/hugetlb.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 98dbfa18bee01d01b40cc7c650cd3eca5eae2457..816e5846222a54255b99515a94e0c1ba9b2b7b27 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3430,6 +3430,9 @@ static unsigned long __init hugetlb_pages_alloc_boot(struct hstate *h)
 		.numa_aware	= true
 	};
 
+	unsigned long jiffies_start;
+	unsigned long jiffies_end;
+
 	job.thread_fn	= hugetlb_pages_alloc_boot_node;
 	job.start	= 0;
 	job.size	= h->max_huge_pages;
@@ -3457,7 +3460,14 @@ static unsigned long __init hugetlb_pages_alloc_boot(struct hstate *h)
 
 	job.max_threads	= hugepage_allocation_threads;
 	job.min_chunk	= h->max_huge_pages / hugepage_allocation_threads;
+
+	jiffies_start = jiffies;
 	padata_do_multithreaded(&job);
+	jiffies_end = jiffies;
+
+	pr_info("HugeTLB: allocation took %dms with hugepage_alloc_threads=%ld\n",
+		jiffies_to_msecs(jiffies_end - jiffies_start),
+		hugepage_allocation_threads);
 
 	return h->nr_huge_pages;
 }

-- 
2.48.1