+ mm-damon-vaddr-consistently-use-only-pmd_entry-for-damos_migrate.patch added to mm-new branch

+ mm-damon-vaddr-consistently-use-only-pmd_entry-for-damos_migrate.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/damon/vaddr: consistently use only pmd_entry for damos_migrate
has been added to the -mm mm-new branch.  Its filename is
     mm-damon-vaddr-consistently-use-only-pmd_entry-for-damos_migrate.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-vaddr-consistently-use-only-pmd_entry-for-damos_migrate.patch

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

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: SeongJae Park <sj@kernel.org>
Subject: mm/damon/vaddr: consistently use only pmd_entry for damos_migrate
Date: Wed, 12 Nov 2025 07:41:08 -0800

For page table walks, it is usual [1] to have only one pmd entry function.
The vaddr.c code for DAMOS_MIGRATE_{HOT,COLD} is not following the
pattern.  Instead, it uses both pmd and pte entry functions without a
special reason.  Refactor it to use only the pmd entry function, to make
the code under mm/ more consistent.

Link: https://lkml.kernel.org/r/20251112154114.66053-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Suggested-by: David Hildenbrand <david@kernel.org>
Cc: Bill Wendling <morbo@google.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/damon/vaddr.c |   88 +++++++++++++++++++--------------------------
 1 file changed, 39 insertions(+), 49 deletions(-)

--- a/mm/damon/vaddr.c~mm-damon-vaddr-consistently-use-only-pmd_entry-for-damos_migrate
+++ a/mm/damon/vaddr.c
@@ -695,7 +695,6 @@ isolate:
 	list_add(&folio->lru, &migration_lists[i]);
 }
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 static int damos_va_migrate_pmd_entry(pmd_t *pmd, unsigned long addr,
 		unsigned long next, struct mm_walk *walk)
 {
@@ -705,58 +704,49 @@ static int damos_va_migrate_pmd_entry(pm
 	struct damos_migrate_dests *dests = &s->migrate_dests;
 	struct folio *folio;
 	spinlock_t *ptl;
-	pmd_t pmde;
-
-	ptl = pmd_lock(walk->mm, pmd);
-	pmde = pmdp_get(pmd);
-
-	if (!pmd_present(pmde) || !pmd_trans_huge(pmde))
-		goto unlock;
-
-	/* Tell page walk code to not split the PMD */
-	walk->action = ACTION_CONTINUE;
-
-	folio = vm_normal_folio_pmd(walk->vma, addr, pmde);
-	if (!folio)
-		goto unlock;
-
-	if (damos_va_filter_out(s, folio, walk->vma, addr, NULL, pmd))
-		goto unlock;
-
-	damos_va_migrate_dests_add(folio, walk->vma, addr, dests,
-		migration_lists);
-
-unlock:
-	spin_unlock(ptl);
-	return 0;
-}
-#else
-#define damos_va_migrate_pmd_entry NULL
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-
-static int damos_va_migrate_pte_entry(pte_t *pte, unsigned long addr,
-		unsigned long next, struct mm_walk *walk)
-{
-	struct damos_va_migrate_private *priv = walk->private;
-	struct list_head *migration_lists = priv->migration_lists;
-	struct damos *s = priv->scheme;
-	struct damos_migrate_dests *dests = &s->migrate_dests;
-	struct folio *folio;
-	pte_t ptent;
-
-	ptent = ptep_get(pte);
-	if (pte_none(ptent) || !pte_present(ptent))
-		return 0;
+	pte_t *start_pte, *pte, ptent;
+	int nr;
 
-	folio = vm_normal_folio(walk->vma, addr, ptent);
-	if (!folio)
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	ptl = pmd_trans_huge_lock(pmd, walk->vma);
+	if (ptl) {
+		pmd_t pmde = pmdp_get(pmd);
+
+		if (!pmd_present(pmde))
+			goto huge_out;
+		folio = vm_normal_folio_pmd(walk->vma, addr, pmde);
+		if (!folio)
+			goto huge_out;
+		if (damos_va_filter_out(s, folio, walk->vma, addr, NULL, pmd))
+			goto huge_out;
+		damos_va_migrate_dests_add(folio, walk->vma, addr, dests,
+				migration_lists);
+huge_out:
+		spin_unlock(ptl);
 		return 0;
+	}
+#endif	/* CONFIG_TRANSPARENT_HUGEPAGE */
 
-	if (damos_va_filter_out(s, folio, walk->vma, addr, pte, NULL))
+	start_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
+	if (!pte)
 		return 0;
 
-	damos_va_migrate_dests_add(folio, walk->vma, addr, dests,
-		migration_lists);
+	for (; addr < next; pte += nr, addr += nr * PAGE_SIZE) {
+		nr = 1;
+		ptent = ptep_get(pte);
+
+		if (pte_none(ptent) || !pte_present(ptent))
+			continue;
+		folio = vm_normal_folio(walk->vma, addr, ptent);
+		if (!folio)
+			continue;
+		if (damos_va_filter_out(s, folio, walk->vma, addr, pte, NULL))
+			return 0;
+		damos_va_migrate_dests_add(folio, walk->vma, addr, dests,
+				migration_lists);
+		nr = folio_nr_pages(folio);
+	}
+	pte_unmap_unlock(start_pte, ptl);
 	return 0;
 }
 
@@ -822,7 +812,7 @@ static unsigned long damos_va_migrate(st
 	struct damos_migrate_dests *dests = &s->migrate_dests;
 	struct mm_walk_ops walk_ops = {
 		.pmd_entry = damos_va_migrate_pmd_entry,
-		.pte_entry = damos_va_migrate_pte_entry,
+		.pte_entry = NULL,
 		.walk_lock = PGWALK_RDLOCK,
 	};
 
_

Patches currently in -mm which might be from sj@kernel.org are

mm-zswap-remove-unnecessary-dlen-writes-for-incompressible-pages.patch
mm-zswap-fix-typos-s-zwap-zswap.patch
mm-zswap-s-red-black-tree-xarray.patch
docs-admin-guide-mm-zswap-s-red-black-tree-xarray.patch
mm-damon-document-damos_quota_goal-nid-use-case.patch
mm-damon-add-damos-quota-goal-type-for-per-memcg-per-node-memory-usage.patch
mm-damon-core-implement-damos_quota_node_memcg_used_bp.patch
mm-damon-sysfs-schemes-implement-path-file-under-quota-goal-directory.patch
mm-damon-sysfs-schemes-support-damos_quota_node_memcg_used_bp.patch
mm-damon-core-add-damos-quota-gaol-metric-for-per-memcg-per-numa-free-memory.patch
mm-damon-sysfs-schemes-support-damos_quota_node_memcg_free_bp.patch
docs-mm-damon-design-document-damos_quota_node_memcg_usedfree_bp.patch
docs-admin-guide-mm-damon-usage-document-damos-quota-goal-path-file.patch
docs-abi-damon-document-damos-quota-goal-path-file.patch
mm-damon-core-fix-wrong-comment-of-damon_call-return-timing.patch
docs-mm-damon-design-fix-wrong-link-to-intervals-goal-section.patch
docs-admin-guide-mm-damon-stat-fix-a-typo-s-sampling-events-sampling-interval.patch
docs-admin-guide-mm-damon-usage-document-empty-target-regions-commit-behavior.patch
docs-admin-guide-mm-damon-reclaim-document-addr_unit-parameter.patch
docs-admin-guide-mm-damon-lru_sort-document-addr_unit-parameter.patch
docs-admin-guide-mm-damon-stat-document-aggr_interval_us-parameter.patch
docs-admin-guide-mm-damon-stat-document-negative-idle-time.patch
mm-damon-core-add-damon_target-obsolete-for-pin-point-removal.patch
mm-damon-sysfs-test-commit-input-against-realistic-destination.patch
mm-damon-sysfs-implement-obsolete_target-file.patch
docs-admin-guide-mm-damon-usage-document-obsolete_target-file.patch
docs-abi-damon-document-obsolete_target-sysfs-file.patch
selftests-damon-_damon_sysfs-support-obsolete_target-file.patch
drgn_dump_damon_status-dump-damon_target-obsolete.patch
sysfspy-extend-assert_ctx_committed-for-monitoring-targets.patch
selftests-damon-sysfs-add-obsolete_target-test.patch
mm-damon-tests-core-kunit-fix-memory-leak-in-damon_test_set_filters_default_reject.patch
mm-damon-tests-core-kunit-handle-allocation-failures-in-damon_test_regions.patch
mm-damon-tests-core-kunit-handle-memory-failure-from-damon_test_target.patch
mm-damon-tests-core-kunit-handle-memory-alloc-failure-from-damon_test_aggregate.patch
mm-damon-tests-core-kunit-handle-alloc-failures-on-damon_test_split_at.patch
mm-damon-tests-core-kunit-handle-alloc-failures-on-damon_test_merge_two.patch
mm-damon-tests-core-kunit-handle-alloc-failures-on-dasmon_test_merge_regions_of.patch
mm-damon-tests-core-kunit-handle-alloc-failures-on-damon_test_split_regions_of.patch
mm-damon-tests-core-kunit-handle-alloc-failures-in-damon_test_ops_registration.patch
mm-damon-tests-core-kunit-handle-alloc-failures-in-damon_test_set_regions.patch
mm-damon-tests-core-kunit-handle-alloc-failures-in-damon_test_update_monitoring_result.patch
mm-damon-tests-core-kunit-handle-alloc-failure-on-damon_test_set_attrs.patch
mm-damon-tests-core-kunit-handle-alloc-failres-in-damon_test_new_filter.patch
mm-damon-tests-core-kunit-handle-alloc-failure-on-damos_test_commit_filter.patch
mm-damon-tests-core-kunit-handle-alloc-failures-on-damos_test_filter_out.patch
mm-damon-tests-core-kunit-handle-alloc-failures-on-damon_test_set_filters_default_reject.patch
mm-damon-tests-vaddr-kunit-handle-alloc-failures-on-damon_do_test_apply_three_regions.patch
mm-damon-tests-vaddr-kunit-handle-alloc-failures-in-damon_test_split_evenly_fail.patch
mm-damon-tests-vaddr-kunit-handle-alloc-failures-on-damon_test_split_evenly_succ.patch
mm-damon-tests-sysfs-kunit-handle-alloc-failures-on-damon_sysfs_test_add_targets.patch
mm-damon-tests-core-kunit-remove-unnecessary-damon_ctx-variable-on-damon_test_split_at.patch
mm-damon-tests-core-kunit-remove-unused-ctx-in-damon_test_split_regions_of.patch
mm-damon-tests-core-kunit-remove-dynamic-allocs-on-damos_test_commit_filter.patch
mm-damon-tests-core-kunit-split-out-damos_test_commit_filter-core-logic.patch
mm-damon-tests-core-kunit-extend-damos_test_commit_filter_for-for-union-fields.patch
mm-damon-tests-core-kunit-add-test-cases-to-damos_test_commit_filter.patch
mm-damon-tests-core-kunit-add-damos_commit_quota_goal-test.patch
mm-damon-tests-core-kunit-add-damos_commit_quota_goals-test.patch
mm-damon-tests-core-kunit-add-damos_commit_quota-test.patch
mm-damon-core-pass-migrate_dests-to-damos_commit_dests.patch
mm-damon-tests-core-kunit-add-damos_commit_dests-test.patch
mm-damon-tests-core-kunit-add-damos_commit-test.patch
mm-damon-tests-core-kunit-add-damon_commit_target_regions-test.patch
mm-damon-rename-damos-core-filter-helpers-to-have-word-core.patch
mm-damon-rename-damos-filters-to-damos-core_filters.patch
mm-damon-vaddr-cleanup-using-pmd_trans_huge_lock.patch
mm-damon-vaddr-use-vm_normal_folio_pmd-instead-of-damon_get_folio.patch
mm-damon-vaddr-consistently-use-only-pmd_entry-for-damos_migrate.patch
mm-damon-tests-core-kunit-remove-damon_min_region-redefinition.patch
selftests-damon-sysfspy-merge-damon-status-dumping-into-commitment-assertion.patch
docs-mm-damon-maintainer-profile-fix-a-typo-on-mm-untable-link.patch
docs-mm-damon-maintainer-profile-fix-grammartical-errors.patch