diff mbox series

[v9,3/4] mm/memory: add any_dirty optional pointer to folio_pte_batch()

Message ID 20240418105750.98866-4-ioworker0@gmail.com (mailing list archive)
State New
Headers show
Series mm/madvise: enhance lazyfreeing with mTHP in madvise_free | expand

Commit Message

Lance Yang April 18, 2024, 10:57 a.m. UTC 
This commit adds the any_dirty pointer as an optional parameter to
folio_pte_batch() function. By using both the any_young and any_dirty pointers,
madvise_free can make smarter decisions about whether to clear the PTEs when
marking large folios as lazyfree.

Suggested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Lance Yang <ioworker0@gmail.com>
---
 mm/internal.h | 12 ++++++++++--
 mm/madvise.c  | 19 ++++++++++++++-----
 mm/memory.c   |  4 ++--
 3 files changed, 26 insertions(+), 9 deletions(-)

Comments

David Hildenbrand April 18, 2024, 11:59 a.m. UTC | #1 
On 18.04.24 12:57, Lance Yang wrote:
> This commit adds the any_dirty pointer as an optional parameter to
> folio_pte_batch() function. By using both the any_young and any_dirty pointers,
> madvise_free can make smarter decisions about whether to clear the PTEs when
> marking large folios as lazyfree.
> 
> Suggested-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Lance Yang <ioworker0@gmail.com>
> ---
>   mm/internal.h | 12 ++++++++++--
>   mm/madvise.c  | 19 ++++++++++++++-----
>   mm/memory.c   |  4 ++--
>   3 files changed, 26 insertions(+), 9 deletions(-)
> 
> diff --git a/mm/internal.h b/mm/internal.h
> index c6483f73ec13..daa59cef85d7 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -134,6 +134,8 @@ static inline pte_t __pte_batch_clear_ignored(pte_t pte, fpb_t flags)
>    *		  first one is writable.
>    * @any_young: Optional pointer to indicate whether any entry except the
>    *		  first one is young.
> + * @any_dirty: Optional pointer to indicate whether any entry except the
> + *		  first one is dirty.
>    *

I was also wondering if we should make that function return a 
pte+nr_pages, instead of only nr_pages, and then simply have the 
function, based on new flags, merge data into the original PTE.

But let's do that separately.

Acked-by: David Hildenbrand <david@redhat.com>
Lance Yang April 18, 2024, 12:09 p.m. UTC | #2 
On Thu, Apr 18, 2024 at 8:00 PM David Hildenbrand <david@redhat.com> wrote:
>
> On 18.04.24 12:57, Lance Yang wrote:
> > This commit adds the any_dirty pointer as an optional parameter to
> > folio_pte_batch() function. By using both the any_young and any_dirty pointers,
> > madvise_free can make smarter decisions about whether to clear the PTEs when
> > marking large folios as lazyfree.
> >
> > Suggested-by: David Hildenbrand <david@redhat.com>
> > Signed-off-by: Lance Yang <ioworker0@gmail.com>
> > ---
> >   mm/internal.h | 12 ++++++++++--
> >   mm/madvise.c  | 19 ++++++++++++++-----
> >   mm/memory.c   |  4 ++--
> >   3 files changed, 26 insertions(+), 9 deletions(-)
> >
> > diff --git a/mm/internal.h b/mm/internal.h
> > index c6483f73ec13..daa59cef85d7 100644
> > --- a/mm/internal.h
> > +++ b/mm/internal.h
> > @@ -134,6 +134,8 @@ static inline pte_t __pte_batch_clear_ignored(pte_t pte, fpb_t flags)
> >    *            first one is writable.
> >    * @any_young: Optional pointer to indicate whether any entry except the
> >    *            first one is young.
> > + * @any_dirty: Optional pointer to indicate whether any entry except the
> > + *             first one is dirty.
> >    *
>

Hey David,

Thanks for taking time to review!

> I was also wondering if we should make that function return a
> pte+nr_pages, instead of only nr_pages, and then simply have the
> function, based on new flags, merge data into the original PTE.
>

Nice, good idea!

> But let's do that separately.

Yep, let's do that separately :p

>
> Acked-by: David Hildenbrand <david@redhat.com>

Thanks again for the review!
Lance

>
> --
> Cheers,
>
> David / dhildenb
>
diff mbox series

Patch

diff --git a/mm/internal.h b/mm/internal.h
index c6483f73ec13..daa59cef85d7 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -134,6 +134,8 @@  static inline pte_t __pte_batch_clear_ignored(pte_t pte, fpb_t flags)
  *		  first one is writable.
  * @any_young: Optional pointer to indicate whether any entry except the
  *		  first one is young.
+ * @any_dirty: Optional pointer to indicate whether any entry except the
+ *		  first one is dirty.
  *
  * Detect a PTE batch: consecutive (present) PTEs that map consecutive
  * pages of the same large folio.
@@ -149,18 +151,20 @@  static inline pte_t __pte_batch_clear_ignored(pte_t pte, fpb_t flags)
  */
 static inline int folio_pte_batch(struct folio *folio, unsigned long addr,
 		pte_t *start_ptep, pte_t pte, int max_nr, fpb_t flags,
-		bool *any_writable, bool *any_young)
+		bool *any_writable, bool *any_young, bool *any_dirty)
 {
 	unsigned long folio_end_pfn = folio_pfn(folio) + folio_nr_pages(folio);
 	const pte_t *end_ptep = start_ptep + max_nr;
 	pte_t expected_pte, *ptep;
-	bool writable, young;
+	bool writable, young, dirty;
 	int nr;
 
 	if (any_writable)
 		*any_writable = false;
 	if (any_young)
 		*any_young = false;
+	if (any_dirty)
+		*any_dirty = false;
 
 	VM_WARN_ON_FOLIO(!pte_present(pte), folio);
 	VM_WARN_ON_FOLIO(!folio_test_large(folio) || max_nr < 1, folio);
@@ -176,6 +180,8 @@  static inline int folio_pte_batch(struct folio *folio, unsigned long addr,
 			writable = !!pte_write(pte);
 		if (any_young)
 			young = !!pte_young(pte);
+		if (any_dirty)
+			dirty = !!pte_dirty(pte);
 		pte = __pte_batch_clear_ignored(pte, flags);
 
 		if (!pte_same(pte, expected_pte))
@@ -193,6 +199,8 @@  static inline int folio_pte_batch(struct folio *folio, unsigned long addr,
 			*any_writable |= writable;
 		if (any_young)
 			*any_young |= young;
+		if (any_dirty)
+			*any_dirty |= dirty;
 
 		nr = pte_batch_hint(ptep, pte);
 		expected_pte = pte_advance_pfn(expected_pte, nr);
diff --git a/mm/madvise.c b/mm/madvise.c
index f5e3699e7b54..4597a3568e7e 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -321,6 +321,18 @@  static inline bool can_do_file_pageout(struct vm_area_struct *vma)
 	       file_permission(vma->vm_file, MAY_WRITE) == 0;
 }
 
+static inline int madvise_folio_pte_batch(unsigned long addr, unsigned long end,
+					  struct folio *folio, pte_t *ptep,
+					  pte_t pte, bool *any_young,
+					  bool *any_dirty)
+{
+	const fpb_t fpb_flags = FPB_IGNORE_DIRTY | FPB_IGNORE_SOFT_DIRTY;
+	int max_nr = (end - addr) / PAGE_SIZE;
+
+	return folio_pte_batch(folio, addr, ptep, pte, max_nr, fpb_flags, NULL,
+			       any_young, any_dirty);
+}
+
 static int madvise_cold_or_pageout_pte_range(pmd_t *pmd,
 				unsigned long addr, unsigned long end,
 				struct mm_walk *walk)
@@ -456,13 +468,10 @@  static int madvise_cold_or_pageout_pte_range(pmd_t *pmd,
 		 * next pte in the range.
 		 */
 		if (folio_test_large(folio)) {
-			const fpb_t fpb_flags = FPB_IGNORE_DIRTY |
-						FPB_IGNORE_SOFT_DIRTY;
-			int max_nr = (end - addr) / PAGE_SIZE;
 			bool any_young;
 
-			nr = folio_pte_batch(folio, addr, pte, ptent, max_nr,
-					     fpb_flags, NULL, &any_young);
+			nr = madvise_folio_pte_batch(addr, end, folio, pte,
+						     ptent, &any_young, NULL);
 			if (any_young)
 				ptent = pte_mkyoung(ptent);
 
diff --git a/mm/memory.c b/mm/memory.c
index 33d87b64d15d..9e07d1b9020c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -989,7 +989,7 @@  copy_present_ptes(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma
 			flags |= FPB_IGNORE_SOFT_DIRTY;
 
 		nr = folio_pte_batch(folio, addr, src_pte, pte, max_nr, flags,
-				     &any_writable, NULL);
+				     &any_writable, NULL, NULL);
 		folio_ref_add(folio, nr);
 		if (folio_test_anon(folio)) {
 			if (unlikely(folio_try_dup_anon_rmap_ptes(folio, page,
@@ -1558,7 +1558,7 @@  static inline int zap_present_ptes(struct mmu_gather *tlb,
 	 */
 	if (unlikely(folio_test_large(folio) && max_nr != 1)) {
 		nr = folio_pte_batch(folio, addr, pte, ptent, max_nr, fpb_flags,
-				     NULL, NULL);
+				     NULL, NULL, NULL);
 
 		zap_present_folio_ptes(tlb, vma, folio, page, pte, ptent, nr,
 				       addr, details, rss, force_flush,