[PATCH 22/46] mm: rmap: provide pte_order in page_vma_mapped_walk

From: James Houghton
Date: Thu Jan 05 2023 - 05:21:37 EST


page_vma_mapped_walk callers will need this information to know how
HugeTLB pages are mapped. pte_order only applies if pte is not NULL.

Signed-off-by: James Houghton <jthoughton@xxxxxxxxxx>
---
include/linux/rmap.h | 1 +
mm/page_vma_mapped.c | 3 +++
2 files changed, 4 insertions(+)

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index bd3504d11b15..e0557ede2951 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -378,6 +378,7 @@ struct page_vma_mapped_walk {
pmd_t *pmd;
pte_t *pte;
spinlock_t *ptl;
+ unsigned int pte_order;
unsigned int flags;
};

diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 4e448cfbc6ef..08295b122ad6 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -16,6 +16,7 @@ static inline bool not_found(struct page_vma_mapped_walk *pvmw)
static bool map_pte(struct page_vma_mapped_walk *pvmw)
{
pvmw->pte = pte_offset_map(pvmw->pmd, pvmw->address);
+ pvmw->pte_order = 0;
if (!(pvmw->flags & PVMW_SYNC)) {
if (pvmw->flags & PVMW_MIGRATION) {
if (!is_swap_pte(*pvmw->pte))
@@ -177,6 +178,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
if (!pvmw->pte)
return false;

+ pvmw->pte_order = huge_page_order(hstate);
pvmw->ptl = huge_pte_lock(hstate, mm, pvmw->pte);
if (!check_pte(pvmw))
return not_found(pvmw);
@@ -272,6 +274,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
}
pte_unmap(pvmw->pte);
pvmw->pte = NULL;
+ pvmw->pte_order = 0;
goto restart;
}
pvmw->pte++;
--
2.39.0.314.g84b9a713c41-goog