mm: page_vma_mapped_walk(): get vma_address_end() earlier

page_vma_mapped_walk() cleanup: get THP's vma_address_end() at the
start, rather than later at next_pte.

It's a little unnecessary overhead on the first call, but makes for a
simpler loop in the following commit.

Link: https://lkml.kernel.org/r/4542b34d-862f-7cb4-bb22-e0df6ce830a2@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Hugh Dickins 2021-06-24 18:39:23 -07:00 committed by Linus Torvalds
parent 474466301d
commit a765c417d8

View File

@ -171,6 +171,15 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
return true;
}
/*
* Seek to next pte only makes sense for THP.
* But more important than that optimization, is to filter out
* any PageKsm page: whose page->index misleads vma_address()
* and vma_address_end() to disaster.
*/
end = PageTransCompound(page) ?
vma_address_end(page, pvmw->vma) :
pvmw->address + PAGE_SIZE;
if (pvmw->pte)
goto next_pte;
restart:
@ -238,10 +247,6 @@ this_pte:
if (check_pte(pvmw))
return true;
next_pte:
/* Seek to next pte only makes sense for THP */
if (!PageTransHuge(page))
return not_found(pvmw);
end = vma_address_end(page, pvmw->vma);
do {
pvmw->address += PAGE_SIZE;
if (pvmw->address >= end)