[RFC PATCH 1/2] procfs: add contpte info into smaps

Anatoly Stepanov
2026-04-15T11:46:59Z

Signed-off-by: Anatoly Stepanov <stepanov.anatoly@huawei.com>
---
fs/proc/task_mmu.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index e091931d7..22bcd36b9 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -874,6 +874,7 @@ struct mem_size_stats {
unsigned long shared_hugetlb;
unsigned long private_hugetlb;
unsigned long ksm;
+ unsigned long cont_pte;
u64 pss;
u64 pss_anon;
u64 pss_file;
@@ -915,7 +916,7 @@ static void smaps_page_accumulate(struct mem_size_stats *mss,

static void smaps_account(struct mem_size_stats *mss, struct page *page,
bool compound, bool young, bool dirty, bool locked,
- bool present)
+ bool present, bool cont)
{
struct folio *folio = page_folio(page);
int i, nr = compound ? compound_nr(page) : 1;
@@ -938,6 +939,8 @@ static void smaps_account(struct mem_size_stats *mss, struct page *page,
mss->ksm += size;

mss->resident += size;
+ if (cont)
+ mss->cont_pte += PAGE_SIZE;
/* Accumulate the size in pages that have been accessed. */
if (young || folio_test_young(folio) || folio_test_referenced(folio))
mss->referenced += size;
@@ -1015,6 +1018,10 @@ static void smaps_pte_hole_lookup(unsigned long addr, struct mm_walk *walk)
#endif
}

+#ifndef pte_cont
+#define pte_cont(pte) (false)
+#endif
+
static void smaps_pte_entry(pte_t *pte, unsigned long addr,
struct mm_walk *walk)
{
@@ -1023,12 +1030,14 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
bool locked = !!(vma->vm_flags & VM_LOCKED);
struct page *page = NULL;
bool present = false, young = false, dirty = false;
+ bool cont = false;
pte_t ptent = ptep_get(pte);

if (pte_present(ptent)) {
page = vm_normal_page(vma, addr, ptent);
young = pte_young(ptent);
dirty = pte_dirty(ptent);
+ cont = pte_cont(ptent);
present = true;
} else if (pte_none(ptent)) {
smaps_pte_hole_lookup(addr, walk);
@@ -1058,7 +1067,7 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
if (!page)
return;

- smaps_account(mss, page, false, young, dirty, locked, present);
+ smaps_account(mss, page, false, young, dirty, locked, present, cont);
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -1096,7 +1105,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
mss->file_thp += HPAGE_PMD_SIZE;

smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd),
- locked, present);
+ locked, present, false);
}
#else
static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,
@@ -1356,6 +1365,11 @@ static void __show_smap(struct seq_file *m, const struct mem_size_stats *mss,
SEQ_PUT_DEC(" kB\nAnonHugePages: ", mss->anonymous_thp);
SEQ_PUT_DEC(" kB\nShmemPmdMapped: ", mss->shmem_thp);
SEQ_PUT_DEC(" kB\nFilePmdMapped: ", mss->file_thp);
+ if (mss->cont_pte) {
+ SEQ_PUT_DEC(" kB\nContPTE(Rss): ", mss->cont_pte);
+ SEQ_PUT_DEC(" ", mss->resident);
+ }
+
SEQ_PUT_DEC(" kB\nShared_Hugetlb: ", mss->shared_hugetlb);
seq_put_decimal_ull_width(m, " kB\nPrivate_Hugetlb: ",
mss->private_hugetlb >> 10, 7);
--
2.34.1