When gbl_reserve is 0, hugetlb_acct_memory() will do nothing except holding and releasing hugetlb_lock. We should avoid this unnecessary hugetlb_lock lock/unlock cycle which is happening on 'most' hugetlb munmap operations by check delta against 0 at the beginning of hugetlb_acct_memory.
Reviewed-by: David Hildenbrand <[email protected]> Signed-off-by: Miaohe Lin <[email protected]> --- mm/hugetlb.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 4f67f6b159c7..da064cb8fd53 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3591,6 +3591,9 @@ static int hugetlb_acct_memory(struct hstate *h, long delta) { int ret = -ENOMEM; + if (!delta) + return 0; + spin_lock(&hugetlb_lock); /* * When cpuset is configured, it breaks the strict hugetlb page -- 2.19.1
