Re: [PATCH v7 3/7] mm,hugetlb: Clear HPageFreed outside of the lock

From: Oscar Salvador
Date: Wed Apr 14 2021 - 06:50:00 EST


On Wed, Apr 14, 2021 at 12:32:58PM +0200, Michal Hocko wrote:
> Well, to be precise it does the very same thing with memamp struct pages
> but that is before the initialization code you have pointed out above.
> In this context it just poisons the allocated content which is the GB
> page storage.

Right.

> > I checked, and when we get there in __alloc_bootmem_huge_page, page->private is
> > still zeroed, so I guess it should be safe to assume that we do not really need
> > to clear the flag in __prep_new_huge_page() routine?
>
> It would be quite nasty if the struct pages content would be undefined.
> Maybe that is possible but then I would rather stick the initialization
> into __alloc_bootmem_huge_page.

Yes, but I do not think that is really possible unless I missed something.
Let us see what Mike thinks of it, if there are no objections, we can
get rid of the clearing flag right there.


--
Oscar Salvador
SUSE L3