The fault_mutex hashing overhead can be avoided in truncate_op case because page faults can not race with truncation in this routine. So calculate hash for fault_mutex only in !truncate_op case to save some cpu cycles.
Reviewed-by: Mike Kravetz <[email protected]> Signed-off-by: Miaohe Lin <[email protected]> Cc: Mike Kravetz <[email protected]> --- v1->v2: remove unnecessary initialization for variable hash collect Reviewed-by tag from Mike Kravetz --- fs/hugetlbfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index c262566f7c5d..f7ec94bc7337 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -485,7 +485,6 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart, u32 hash; index = page->index; - hash = hugetlb_fault_mutex_hash(mapping, index); if (!truncate_op) { /* * Only need to hold the fault mutex in the @@ -493,6 +492,7 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart, * page faults. Races are not possible in the * case of truncation. */ + hash = hugetlb_fault_mutex_hash(mapping, index); mutex_lock(&hugetlb_fault_mutex_table[hash]); } -- 2.19.1
