Re: [External] RE: [PATCH v4 00/21] Free some vmemmap pages of hugetlb page

[Muchun Song]

On Wed, Nov 18, 2020 at 3:45 AM Oscar Salvador <osalvador@xxxxxxx> wrote:
>
> On 2020-11-17 17:29, Muchun Song wrote:
> > Now for the 2MB HugrTLB page, we only free 6 vmemmap pages.
> > But your words woke me up. Maybe we really can free 7 vmemmap
> > pages. In this case, we can see 8 of the 512 struct page structures
> > has beed set PG_head flag. If we can adjust compound_head()
> > slightly and make compound_head() return the real head struct
> > page when the parameter is the tail struct page but with PG_head
> > flag set. I will start an investigation and a test.
>
> I would not overcomplicate things at this stage, but rather keep it
> simple as the code is already tricky enough(without counting the LOC
> thatvit adds).
> We can always build on top later on in order to improve things.

I think that this improvement can be a separate patch. In this case,
it can make the code evolution route clearer.

Thanks.


>
> --
> Oscar Salvador
> SUSE L3



-- 
Yours,
Muchun