Hi:
On 2021/3/13 4:03, Mike Kravetz wrote:
> On 3/8/21 3:28 AM, Miaohe Lin wrote:
>> 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.
>>
>> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
>> ---
>> fs/hugetlbfs/inode.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
>> index c262566f7c5d..d81f52b87bd7 100644
>> --- a/fs/hugetlbfs/inode.c
>> +++ b/fs/hugetlbfs/inode.c
>> @@ -482,10 +482,9 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart,
>>
>> for (i = 0; i < pagevec_count(&pvec); ++i) {
>> struct page *page = pvec.pages[i];
>> - u32 hash;
>> + u32 hash = 0;
>
> Do we need to initialize hash here?
> I would not bring this up normally, but the purpose of the patch is to save
> cpu cycles.
The hash is initialized here in order to avoid false positive
"uninitialized local variable used" warning. Or this is indeed unnecessary?
Many thanks for review.
>
