2024-04-17 09:24:12

by David Hildenbrand

[permalink] [raw]
Subject: [PATCH v1 0/2] fs/proc/task_mmu: convert hugetlb functions to work on folis

Let's convert two more functions, getting rid of two more page_mapcount()
calls.

Cc: Andrew Morton <[email protected]>
Cc: Muchun Song <[email protected]>

David Hildenbrand (2):
fs/proc/task_mmu: convert pagemap_hugetlb_range() to work on folios
fs/proc/task_mmu: convert smaps_hugetlb_range() to work on folios

fs/proc/task_mmu.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

--
2.44.0



2024-04-17 09:24:34

by David Hildenbrand

[permalink] [raw]
Subject: [PATCH v1 1/2] fs/proc/task_mmu: convert pagemap_hugetlb_range() to work on folios

Let's get rid of another page_mapcount() check and simply use
folio_likely_mapped_shared(), which is precise for hugetlb folios.

While at it, also check for PMD table sharing, like we do in
smaps_hugetlb_range().

No functional change intended, except that we would now detect hugetlb
folios shared via PMD table sharing correctly.

Signed-off-by: David Hildenbrand <[email protected]>
---
fs/proc/task_mmu.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 8ff79bd427ec6..cd6e45e0cde8e 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1578,12 +1578,13 @@ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,

pte = huge_ptep_get(ptep);
if (pte_present(pte)) {
- struct page *page = pte_page(pte);
+ struct folio *folio = page_folio(pte_page(pte));

- if (!PageAnon(page))
+ if (!folio_test_anon(folio))
flags |= PM_FILE;

- if (page_mapcount(page) == 1)
+ if (!folio_likely_mapped_shared(folio) &&
+ !hugetlb_pmd_shared(ptep))
flags |= PM_MMAP_EXCLUSIVE;

if (huge_pte_uffd_wp(pte))
--
2.44.0


2024-04-17 10:23:58

by Oscar Salvador

[permalink] [raw]
Subject: Re: [PATCH v1 1/2] fs/proc/task_mmu: convert pagemap_hugetlb_range() to work on folios

On Wed, Apr 17, 2024 at 11:23:12AM +0200, David Hildenbrand wrote:
> Let's get rid of another page_mapcount() check and simply use
> folio_likely_mapped_shared(), which is precise for hugetlb folios.
>
> While at it, also check for PMD table sharing, like we do in
> smaps_hugetlb_range().
>
> No functional change intended, except that we would now detect hugetlb
> folios shared via PMD table sharing correctly.
>
> Signed-off-by: David Hildenbrand <[email protected]>

Reviewed-by: Oscar Salvador <[email protected]>



--
Oscar Salvador
SUSE Labs