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

From: Miaohe Lin
Date: Fri Jan 15 2021 - 04:45:26 EST


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 ?

>
> Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
>
>

Many thanks for your review.