On Wed, Jan 03, 2024 at 05:14:21PM +0800, peterx@redhat.com wrote:

From: Peter Xu <peterx@redhat.com>

Replace pmd_trans_huge() with pmd_thp_or_huge() to also cover pmd_huge() as
long as enabled.

FOLL_TOUCH and FOLL_SPLIT_PMD only apply to THP, not yet huge.

Since now follow_trans_huge_pmd() can process hugetlb pages, renaming it
into follow_huge_pmd() to match what it does.  Move it into gup.c so not
depend on CONFIG_THP.

When at it, move the ctx->page_mask setup into follow_huge_pmd(), only set
it when the page is valid.  It was not a bug to set it before even if GUP
failed (page==NULL), because follow_page_mask() callers always ignores
page_mask if so.  But doing so makes the code cleaner.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 mm/gup.c         | 107 ++++++++++++++++++++++++++++++++++++++++++++---
 mm/huge_memory.c |  86 +------------------------------------
 mm/internal.h    |   5 +--
 3 files changed, 105 insertions(+), 93 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason