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mm-damon-core-handle-unreset-probe_hits-in-probe_hits_mvsum.patch removed from -mm tree

merged mm-stable Andrew Morton 1 participant 1 message Aug 5

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The quilt patch titled
Subject: mm/damon/core: handle unreset probe_hits in probe_hits_mvsum()
has been removed from the -mm tree. Its filename was
mm-damon-core-handle-unreset-probe_hits-in-probe_hits_mvsum.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 <[email protected]>
Subject: mm/damon/core: handle unreset probe_hits in probe_hits_mvsum()
Date: Wed, 8 Jul 2026 06:53:57 -0700

If damon_update_monitoring_result() is called at the end of the aggregation interval, probe_hits is not reset. That's because the value will be exposed to the user via damon_region_aggregated trace event.

Meanwhile, damon_probe_hits_mvsum() can be called in this state. Due to its logic, it will return a value that is incorrectly high. This could happen if the user requested DAMOS schemes applied regions sysfs files update exactly in the time sequence.

The impact is minor, but better to avoid. Check the timing and simply return the fully aggregated last_probe_hits, like damon_nr_accesses_mvsum() also does. It is not 100% accurate since it is the last interval's aggregation. But better than the value that is completely reset.

---

 mm/damon/core.c |    3 +++
 1 file changed, 3 insertions(+)
mm/damon/core.c renamed from mm/damon/core.c~mm-damon-core-handle-unreset-probe_hits-in-probe_hits_mvsum +3 -0
@@ -290,6 +290,9 @@ unsigned char damon_probe_hits_mvsum(int
 			ctx->passed_sample_intervals;
 	left_window_bp = mult_frac(left_window, 10000, window_len);
 
+	if (left_window_bp == 10000)
+		return r->last_probe_hits[probe_idx];
+
 	return damon_mvsum(r->probe_hits[probe_idx],
 			r->last_probe_hits[probe_idx], left_window_bp);
 }

_

Patches currently in -mm which might be from [email protected] are

mm-damon-adjust-isolated-pages-stat-for-damos_migrate_hotcold.patch samples-damon-mtier-error-out-for-zero-quota-goal-target-values.patch mm-damon-lru_sort-error-out-for-10000-active_mem_bp.patch mm-damon-reclaim-skip-damon_call-if-ctx-has-not-started.patch mm-damon-lru_sort-skip-damon_call-if-ctx-has-not-started.patch mm-damon-core-skip-aging-from-repeated-aggressive-merging.patch mm-damon-core-hide-private-damon_region-fields.patch mm-damon-core-hide-private-damon_target-fields.patch mm-damon-core-hide-private-damos_quota_goal-fields.patch mm-damon-core-hide-private-damos_quota-fields.patch mm-damon-core-hide-private-damos_filter-fields.patch mm-damon-core-hide-private-damos-fields.patch mm-damon-core-hide-private-damon_filter-fields.patch mm-damon-core-hide-private-damon_probe-fields.patch mm-damon-sysfs-do-not-directly-access-damon_ctx-ops.patch mm-damon-core-hide-core-private-damon_ctx-fields.patch mm-damon-core-avoid-infinite-kdamond_merge_regions-internal-loop.patch mm-damon-tests-core-kunit-catch-test-failure-in-test_merge_regions_of.patch mm-damon-vaddr-drop-last-same-folio-access-check-optimization.patch mm-damon-paddr-drop-last-same-folio-access-check-reuse-optimization.patch mm-damon-sysfs-read-addr_unit-only-once-in-damon_sysfs_apply_inputs.patch mm-damon-sysfs-read-ops_id-only-once-in-damon_sysfs_apply_inputs.patch mm-damon-core-initialize-damos-last_applied.patch mm-damon-core-kunit-check-region-count-before-testing-in-split_at.patch mm-damon-vaddr-kunit-check-region-count-in-three_regions-test.patch mm-damon-core-kunit-handle-region-split-failure-in-filter_out.patch mm-damon-core-kunit-skip-wrong-dest-walk-in-commit_dests_for.patch mm-damon-core-kunit-skip-wrong-quota-goal-walk-in-commit_quota_goals.patch mm-damon-core-kunit-skip-wrong-region-walk-in-commit_target_regions.patch mm-damon-ops-common-use-nr_accesses-moving-sum-for-quota-score.patch mm-damon-core-handle-region-split-failure-in-apply_min_nr_regions.patch