Re: [External] Re: [PATCH v15 4/8] mm: hugetlb: alloc the vmemmap pages associated with each HugeTLB page

From: Mike Kravetz
Date: Wed Feb 17 2021 - 20:02:40 EST


On 2/17/21 12:13 AM, Michal Hocko wrote:
> On Tue 16-02-21 11:44:34, Mike Kravetz wrote:
> [...]
>> If we are not going to do the allocations under the lock, then we will need
>> to either preallocate or take the workqueue approach.
>
> We can still drop the lock temporarily right? As we already do before
> calling destroy_compound_gigantic_page...
>

Yes we can. I forgot about that.

Actually, very little of what update_and_free_page does needs to be done
under the lock. Perhaps, just decrementing the global count and clearing
the destructor so PageHuge() is no longer true.
--
Mike Kravetz