Re: [RFC PATCH 19/26] hugetlb: add HGM support for copy_hugetlb_page_range

From: Mike Kravetz
Date: Mon Jul 11 2022 - 19:41:31 EST


On 06/24/22 17:36, James Houghton wrote:
> This allows fork() to work with high-granularity mappings. The page
> table structure is copied such that partially mapped regions will remain
> partially mapped in the same way for the new process.
>
> Signed-off-by: James Houghton <jthoughton@xxxxxxxxxx>
> ---
> mm/hugetlb.c | 74 +++++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 59 insertions(+), 15 deletions(-)

FYI -
With https://lore.kernel.org/linux-mm/20220621235620.291305-5-mike.kravetz@xxxxxxxxxx/
copy_hugetlb_page_range() should never be called for shared mappings.
Since HGM only works on shared mappings, code in this patch will never
be executed.

I have a TODO to remove shared mapping support from copy_hugetlb_page_range.
--
Mike Kravetz