Re: [PATCH v2] mm/hugetlb: avoid unnecessary hugetlb_acct_memory() call

From: Mike Kravetz
Date: Tue Jan 19 2021 - 17:26:29 EST


On 1/15/21 1:44 AM, Miaohe Lin wrote:
> Hi:
>
> On 2021/1/15 17:28, Oscar Salvador wrote:
>> On Fri, Jan 15, 2021 at 04:20:13AM -0500, Miaohe Lin wrote:
>>> 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 <david@xxxxxxxxxx>
>>> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
>>
>> I would avoid mentioning gbl_reserve as not all callers use it, and focus
>> on what delta means:
>>
>> "When reservation accounting remains unchanged..", but anyway:
>
> Sounds good. Maybe Andrew could kindly do this if this patch is picked up ?

Thank you and Andrew.

Looks like Andrew updated the commit message and added to his tree.

--
Mike Kravetz