From: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> Subject: mm/hugetlb: use list_splice to merge two list at once 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. Link: https://lkml.kernel.org/r/20200831022351.20916-4-richard.weiyang@xxxxxxxxxxxxxxxxx Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> Reviewed-by: Baoquan He <bhe@xxxxxxxxxx> Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/hugetlb.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) --- a/mm/hugetlb.c~mm-hugetlb-use-list_splice-to-merge-two-list-at-once +++ a/mm/hugetlb.c @@ -443,11 +443,8 @@ static int allocate_file_region_entries( 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; _
