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From:   Wei Yang <richard.weiyang@linux.alibaba.com>
To:     mike.kravetz@oracle.com, akpm@linux-foundation.org
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org, bhe@redhat.com,
        Wei Yang <richard.weiyang@linux.alibaba.com>
Subject: [Patch v2 3/7] mm/hugetlb: use list_splice to merge two list at once
Date:   Fri, 28 Aug 2020 11:32:38 +0800
Message-Id: <20200828033242.8787-4-richard.weiyang@linux.alibaba.com>
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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@linux.alibaba.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
---
 mm/hugetlb.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index f325839be617..cbe67428bf99 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -441,11 +441,8 @@ 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)