+ mm-mlock-implement-folio_mlock_step-using-folio_pte_batch.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/mlock: implement folio_mlock_step() using folio_pte_batch()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-mlock-implement-folio_mlock_step-using-folio_pte_batch.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mlock-implement-folio_mlock_step-using-folio_pte_batch.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Lance Yang <ioworker0@gmail.com>
Subject: mm/mlock: implement folio_mlock_step() using folio_pte_batch()
Date: Tue, 11 Jun 2024 09:04:18 +0800

Let's make folio_mlock_step() simply a wrapper around folio_pte_batch(),
which will greatly reduce the cost of ptep_get() when scanning a range of
contptes.

Link: https://lkml.kernel.org/r/20240611010418.70797-1-ioworker0@gmail.com
Signed-off-by: Lance Yang <ioworker0@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Suggested-by: Barry Song <21cnbao@gmail.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Bang Li <libang.li@antgroup.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mlock.c |   19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

--- a/mm/mlock.c~mm-mlock-implement-folio_mlock_step-using-folio_pte_batch
+++ a/mm/mlock.c
@@ -307,26 +307,15 @@ void munlock_folio(struct folio *folio)
 static inline unsigned int folio_mlock_step(struct folio *folio,
 		pte_t *pte, unsigned long addr, unsigned long end)
 {
-	unsigned int count, i, nr = folio_nr_pages(folio);
-	unsigned long pfn = folio_pfn(folio);
+	const fpb_t fpb_flags = FPB_IGNORE_DIRTY | FPB_IGNORE_SOFT_DIRTY;
+	unsigned int count = (end - addr) >> PAGE_SHIFT;
 	pte_t ptent = ptep_get(pte);
 
 	if (!folio_test_large(folio))
 		return 1;
 
-	count = pfn + nr - pte_pfn(ptent);
-	count = min_t(unsigned int, count, (end - addr) >> PAGE_SHIFT);
-
-	for (i = 0; i < count; i++, pte++) {
-		pte_t entry = ptep_get(pte);
-
-		if (!pte_present(entry))
-			break;
-		if (pte_pfn(entry) - pfn >= nr)
-			break;
-	}
-
-	return i;
+	return folio_pte_batch(folio, addr, pte, ptent, count, fpb_flags, NULL,
+			       NULL, NULL);
 }
 
 static inline bool allow_mlock_munlock(struct folio *folio,
_

Patches currently in -mm which might be from ioworker0@gmail.com are

mm-rmap-remove-duplicated-exit-code-in-pagewalk-loop.patch
mm-rmap-add-helper-to-restart-pgtable-walk-on-changes.patch
mm-rmap-integrate-pmd-mapped-folio-splitting-into-pagewalk-loop.patch
mm-vmscan-avoid-split-lazyfree-thp-during-shrink_folio_list.patch
mm-mlock-implement-folio_mlock_step-using-folio_pte_batch.patch