[PATCH 2/2] mm: hugetlb: log time needed to allocate hugepages

From: Thomas Prescher via B4 Relay
Date: Fri Feb 21 2025 - 08:49:32 EST


From: Thomas Prescher <thomas.prescher@xxxxxxxxxxxxxxxxxxxxx>

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

Signed-off-by: Thomas Prescher <thomas.prescher@xxxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b7d24c41e0f9d22f5b86c253e29a2eca28460026..2aa5724a385494f9d6f1d644a2bfe547591fc96c 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3428,6 +3428,9 @@ 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;
@@ -3450,7 +3453,13 @@ static unsigned long __init hugetlb_pages_alloc_boot(struct hstate *h)
*/
job.max_threads = num_node_state(N_MEMORY) * allocation_threads_per_node;
job.min_chunk = h->max_huge_pages / num_node_state(N_MEMORY) / allocation_threads_per_node;
+
+ jiffies_start = jiffies;
padata_do_multithreaded(&job);
+ jiffies_end = jiffies;
+
+ printk(KERN_DEBUG "HugeTLB: allocation took %dms\n",
+ jiffies_to_msecs(jiffies_end - jiffies_start));

return h->nr_huge_pages;
}

--
2.48.1