On 2021/3/14 5:17, Mike Kravetz wrote: > On 3/12/21 6:49 PM, Miaohe Lin wrote: >> 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 <[email protected]> >>>> --- >>>> 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? >> > > Of course. In this case we know more about usage then the compiler. > You can add: >
I see. Many thanks. Am I supposed to resend the whole v2 patch series ? Or just a single v2 patch with change mentioned above? Please let me know which is the easiest one for you. > Reviewed-by: Mike Kravetz <[email protected]> >
