On 2/17/21 11:35 AM, Peter Xu wrote:

On Wed, Feb 10, 2021 at 04:03:20PM -0800, Mike Kravetz wrote:

quoted

Pagemap was only using the vma flag PM_SOFT_DIRTY for hugetlb vmas.
This is insufficient.  Check the individual pte entries.

Signed-off-by: Mike Kravetz <redacted>
---
 fs/proc/task_mmu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 602e3a52884d..829b35016aaa 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c

@@ -1507,6 +1507,10 @@ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
 		flags |= PM_SOFT_DIRTY;
 
 	pte = huge_ptep_get(ptep);
+
+	if (huge_pte_soft_dirty(pte))
+		flags |= PM_SOFT_DIRTY;

Should this be put into pte_present() chunk below?  Since I feel like we'd need
huge_pte_swp_soft_dirty() for !pte_present().  Say, _PAGE_SOFT_DIRTY and
_PAGE_SWP_SOFT_DIRTY can be different.

Yes this should be moved below, and it should check for both.

Thanks,
-- 
Mike Kravetz

quoted

+
 	if (pte_present(pte)) {
 		struct page *page = pte_page(pte);
 
-- 
2.29.2