Later in the series, we want to find a pmd and take different actions,
depending on if the pmd maps a thp or not. Currently, mm_find_pmd()
returns NULL if a valid pmd maps a thp, and so we can't use it directly.
Split mm_find_pmd() into 2 parts: mm_find_pmd_raw(), which returns a
raw pmd pointer, and the logic that filters out non-present none, or
huge pmds. mm_find_pmd_raw() can then be reused later in the series.
Signed-off-by: Zach O'Keefe <zokeefe@xxxxxxxxxx>
---
mm/internal.h | 1 +
mm/rmap.c | 15 +++++++++++++--
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index 86277d90a5e2..aaea25bb9096 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -166,6 +166,7 @@ extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason
/*
* in mm/rmap.c:
*/
+pmd_t *mm_find_pmd_raw(struct mm_struct *mm, unsigned long address);
extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
/*
diff --git a/mm/rmap.c b/mm/rmap.c
index 70375c331083..0ae99affcb27 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -758,13 +758,12 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
return vma_address(page, vma);
}
-pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address)
+pmd_t *mm_find_pmd_raw(struct mm_struct *mm, unsigned long address)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd = NULL;
- pmd_t pmde;
pgd = pgd_offset(mm, address);
if (!pgd_present(*pgd))
@@ -779,6 +778,18 @@ pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address)
goto out;
pmd = pmd_offset(pud, address);
+out:
+ return pmd;
+}
+
+pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address)
+{
+ pmd_t pmde;
+ pmd_t *pmd;
+
+ pmd = mm_find_pmd_raw(mm, address);
+ if (!pmd)
+ goto out;
/*
* Some THP functions use the sequence pmdp_huge_clear_flush(), set_pmd_at()
* without holding anon_vma lock for write. So when looking for a
--
2.35.1.616.g0bdcbb4464-goog
