Messages in this thread | | | Date | Wed, 16 Dec 2020 15:03:40 +0100 | From | Oscar Salvador <> | Subject | Re: [PATCH v9 10/11] mm/hugetlb: Gather discrete indexes of tail page |
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On Sun, Dec 13, 2020 at 11:45:33PM +0800, Muchun Song wrote: > For HugeTLB page, there are more metadata to save in the struct page. > But the head struct page cannot meet our needs, so we have to abuse > other tail struct page to store the metadata. In order to avoid > conflicts caused by subsequent use of more tail struct pages, we can > gather these discrete indexes of tail struct page. In this case, it > will be easier to add a new tail page index later. > > There are only (RESERVE_VMEMMAP_SIZE / sizeof(struct page)) struct > page structs can be used when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP, so "that can be..."
> add a BUILD_BUG_ON to catch invalid usage of the tail struct page. > > Signed-off-by: Muchun Song <songmuchun@bytedance.com>
I think this makes the current situation with metadata usage in sub-pages easier to track.
Reviewed-by: Oscar Salvador <osalvador@suse.de>
-- Oscar Salvador SUSE L3
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