[Patch v3 3/7] mm/hugetlb: use list_splice to merge two list at once

From: Wei Yang
Date: Sun Aug 30 2020 - 22:24:31 EST


Instead of add allocated file_region one by one to region_cache, we
could use list_splice to merge two list at once.

Also we know the number of entries in the list, increase the number
directly.

Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx>
Reviewed-by: Baoquan He <bhe@xxxxxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
mm/hugetlb.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index fbaf49bc1d26..a02bf430de6f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -443,11 +443,8 @@ static int allocate_file_region_entries(struct resv_map *resv,

spin_lock(&resv->lock);

- list_for_each_entry_safe(rg, trg, &allocated_regions, link) {
- list_del(&rg->link);
- list_add(&rg->link, &resv->region_cache);
- resv->region_cache_count++;
- }
+ list_splice(&allocated_regions, &resv->region_cache);
+ resv->region_cache_count += to_allocate;
}

return 0;
--
2.20.1 (Apple Git-117)