[merged mm-stable] mm-damon-vaddr-respect-folio-end-for-damos_stat.patch removed from -mm tree

[merged mm-stable] mm-damon-vaddr-respect-folio-end-for-damos_stat.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/damon/vaddr: respect folio end for DAMOS_STAT
has been removed from the -mm tree.  Its filename was
     mm-damon-vaddr-respect-folio-end-for-damos_stat.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: SJ Park <sj@kernel.org>
Subject: mm/damon/vaddr: respect folio end for DAMOS_STAT
Date: Tue, 1 Sep 2026 06:18:45 -0700

For applying DAMOS_STAT action to a region, DAMON virtual address space
operation set (vaddr) calls walk_page_range[_vma]() for the region.  The
pmd walk entry function, namely damon_va_stat_pmd_entry(), applies DAMOS
filters to folios of addresses of the region in the pmd.  It starts from
the walking address and advances the address by the size of the folio of
the address until it goes out of the pmd or the region.

Let's suppose it is for the first pmd of the region, and the region start
address is in the middle of a large folio.  Also, the next folios are
small.  Then, some of the next folios could be skipped.  Fix the issue by
advancing the address to exactly the start address of the next folio.

The user impact is that the DAMOS_STAT-based page level monitoring results
become inaccurate.  Since the page level monitoring is supposed to provide
relatively high precision, this is definitely a problem.  It is arguably
not critical since it is only monitoring quality degradation.

The issue was discovered [1] by Sashiko.

Link: https://lore.kernel.org/20260901131850.98037-5-sj@kernel.org
Link: https://lore.kernel.org/20260514015053.149396-1-sj@kernel.org [1]
Fixes: 63f39737d1e3 ("mm/damon/vaddr: support stat-purpose DAMOS filters")
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: <stable@vger.kernel.org> # 6.18.x
---

 mm/damon/vaddr.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/mm/damon/vaddr.c~mm-damon-vaddr-respect-folio-end-for-damos_stat
+++ a/mm/damon/vaddr.c
@@ -838,6 +838,8 @@ huge_unlock:
 		return 0;
 
 	for (; addr < next; pte += nr, addr += nr * PAGE_SIZE) {
+		unsigned long page_idx;
+
 		nr = 1;
 		ptent = ptep_get(pte);
 
@@ -851,7 +853,8 @@ huge_unlock:
 
 		if (!damos_va_filter_out(s, folio, vma, addr, pte, NULL))
 			*sz_filter_passed += folio_size(folio);
-		nr = folio_nr_pages(folio);
+		page_idx = folio_page_idx(folio, pte_page(ptent));
+		nr = folio_nr_pages(folio) - page_idx;
 		s->last_applied = folio;
 	}
 	pte_unmap_unlock(start_pte, ptl);
_

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

mm-damon-core-use-damon_nr_samples_per_aggr-for-max-merge-threshold.patch
mm-damon-core-remove-debug-messages.patch
mm-damon-core-remove-debug-messages-fix.patch
mm-damon-vaddr-remove-a-debug-message.patch
mm-damon-core-validate-number-of-probes-in-valid_probe_params.patch
mm-damon-sysfs-remove-probes-number-validation.patch
mm-damon-tests-core-kunit-extend-set_regions-test-for-error-case.patch
mm-damon-tests-core-kunit-test-=0-size-damon_set_regions-inputs.patch
mm-damon-tests-core-kunit-test-overlapping-ranges-for-set_regions.patch
mm-damon-tests-core-kunit-test-damon_nr_samples_per_aggr.patch
selftests-damon-sysfssh-test-hugepage_mem_bp-quota-goal.patch
docs-mm-damon-maintainer-profile-update-ai-review-for-sashiko-replies.patch
docs-abi-damon-recommend-subsystem-doc-instead-of-admin-guide.patch
mm-damon-core-error-damos_commit_quota_goal-for-zero-target_value.patch
revert-mm-damon-lru_sort-error-out-for-10000-active_mem_bp.patch
revert-samples-damon-mtier-error-out-for-zero-quota-goal-target-values.patch
mm-damon-core-handle-null-ctx-parameter-in-damon_call.patch
mm-damon-core-set-ctx-call_controls_obsolete-in-damon_new_ctx.patch
mm-damon-reclaim-remove-unnecessary-damon_call-param-validation.patch
mm-damon-lru_sort-remove-unnecessary-damon_call-param-validation.patch
mm-damon-vaddr-support-prep_probes.patch
mm-damon-paddr-move-probe-filter-handling-to-ops-common.patch
mm-damon-vaddr-support-apply_probe.patch
mm-damon-vaddr-extend-apply_probes-for-hugetlb.patch
mm-damon-vaddr-support-pgidle_unset-probe-filter-type.patch
mm-damon-api-introduce-damon_filter_type_pgidle_set.patch
mm-damon-paddr-support-damon_filter_type_pgidle_set.patch
mm-damon-vaddr-support-damon_filter_type_pgidle_set.patch
mm-damon-sysfs-support-damon_filter_type_pgidle_set.patch
docs-mm-damon-design-update-for-pgidle_set-probe-filter.patch
mm-damon-api-introduce-damos_filter_type_probe_hits_wsum.patch
mm-damon-api-introduce-damos_filter_type_probe_hits_wsum-fix.patch
mm-damon-core-extend-probe_hits_wsum-for-moving-sum-based-calculation.patch
mm-damon-core-support-probe_hits_wsum-damos-core-filter.patch
mm-damon-sysfs-schemes-rename-sysfs_filter-sz_range-to-range_minmax.patch
mm-damon-sysfs-schemes-support-probe_hits_wsum-damos-core-filter.patch
docs-mm-damon-design-update-for-probe_hits_wsum-damos-core-filter.patch
docs-admin-guide-mm-damon-usage-update-for-probe_hits_wsum-damos-filter.patch
mm-damon-sysfs-schemes-read-sysfs_filter-addr_range-only-once.patch
mm-damon-sysfs-schemes-read-sysfs_filter-sz_range-only-once.patch
mm-damon-core-return-an-error-from-damos_commit_filter_arg.patch
mm-damon-core-disallow-max-min-damos-filter-range-arguments-commit.patch
mm-damon-sysfs-schemes-drop-centralized-filter-range-arg-validations.patch
mm-damon-sysfs-schemes-use-switch-case-in-add_scheme_filters.patch
mm-damon-core-kunit-extend-damos_commit_filter_for-for-wrong-input.patch
mm-damon-core-kunit-test-invalid-damos-filter-commits.patch
mm-damon-api-introduce-damon_filter_type_hugepage_size.patch
mm-damon-core-commit-hugepage_size-type-damon-filter.patch
mm-damon-ops-common-support-hugepage_size-damon-filter-matching.patch
mm-damon-sysfs-add-minmax-files-under-probe-filter-directory.patch
mm-damon-sysfs-support-hugepage_size-probe-filter.patch
docs-mm-damon-design-update-for-hugepage_size-probe-filter.patch
docs-admin-guide-mm-damon-usage-update-for-hugepage_size.patch
docs-abi-damon-update-for-hugepage_size-probe-filter.patch
mm-damon-api-remove-nr_damos_filter_types.patch
mm-damon-core-use-abs_diff-in-damon_feed_loop_next_input.patch
mm-damon-core-use-mult_frac-in-damon_feed_loop_next_input.patch
mm-damon-core-set-damon_ctx-walk_control_obsolete-in-damon_new_ctx.patch
mm-damon-core-document-damon_call-damon_start-race-hang-issue.patch
mm-damon-paddr-remove-pa-parameter-from-damon_pa_filter_pass.patch
mm-damon-tests-core-kunit-test-eligible_mem_bp-commitment.patch
mm-damon-tests-core-kunit-add-probe_hits_wsum-damos-filter-commit-test.patch
selftests-damon-sysfs_memcg_path_leak-fail-only-for-real-damon-leak.patch
docs-mm-damon-design-clarify-bp-is-basis-point.patch
mm-damon-core-introduce-damos_quota_goal-complement.patch
mm-damon-core-add-complement-argument-to-damos_new_quota_goal.patch
mm-damon-sysfs-schemes-support-quota-goal-complement-flag.patch
mm-damon-tests-core-kunit-test-quota_goal-complement-commit.patch
selftests-damon-sysfssh-test-quota-goal-complement-flag-file.patch
docs-mm-damon-design-document-damos-quota-goal-complement-flag.patch
docs-admin-guide-mm-damon-usage-update-for-quota-goal-complement-file.patch
docs-abi-damon-update-for-quota-goal-metric-complement-sysfs-file.patch