+ mm-damon-core-use-damon_nr_accesses_mvsum-for-damos-region-tracing.patch added to mm-new branch

+ mm-damon-core-use-damon_nr_accesses_mvsum-for-damos-region-tracing.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/damon/core: use damon_nr_accesses_mvsum() for damos region tracing
has been added to the -mm mm-new branch.  Its filename is
     mm-damon-core-use-damon_nr_accesses_mvsum-for-damos-region-tracing.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-core-use-damon_nr_accesses_mvsum-for-damos-region-tracing.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.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: SJ Park <sj@kernel.org>
Subject: mm/damon/core: use damon_nr_accesses_mvsum() for damos region tracing
Date: Mon, 29 Jun 2026 21:07:59 -0700

damon_nr_accesses_mvsum() returns a value same to nr_accesses_bp.  Also
the function is more simple and therefore more tolerant to errors. 
Execution of the function would be more expensive than the simple read of
the field, but because the function is quite simple, the overhead should
be negligible.  Use it in the DAMON region exporting trace points instead
of the nr_accesses_bp.

Link: https://lore.kernel.org/20260630040812.149729-7-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/trace/events/damon.h |    8 +++++---
 mm/damon/core.c              |    5 +++--
 2 files changed, 8 insertions(+), 5 deletions(-)

--- a/include/trace/events/damon.h~mm-damon-core-use-damon_nr_accesses_mvsum-for-damos-region-tracing
+++ a/include/trace/events/damon.h
@@ -78,9 +78,11 @@ TRACE_EVENT_CONDITION(damos_before_apply
 
 	TP_PROTO(unsigned int context_idx, unsigned int scheme_idx,
 		unsigned int target_idx, struct damon_region *r,
-		unsigned int nr_regions, bool do_trace),
+		unsigned int nr_accesses, unsigned int nr_regions,
+		bool do_trace),
 
-	TP_ARGS(context_idx, scheme_idx, target_idx, r, nr_regions, do_trace),
+	TP_ARGS(context_idx, scheme_idx, target_idx, r, nr_accesses,
+		nr_regions, do_trace),
 
 	TP_CONDITION(do_trace),
 
@@ -101,7 +103,7 @@ TRACE_EVENT_CONDITION(damos_before_apply
 		__entry->target_idx = target_idx;
 		__entry->start = r->ar.start;
 		__entry->end = r->ar.end;
-		__entry->nr_accesses = r->nr_accesses_bp / 10000;
+		__entry->nr_accesses = nr_accesses;
 		__entry->age = r->age;
 		__entry->nr_regions = nr_regions;
 	),
--- a/mm/damon/core.c~mm-damon-core-use-damon_nr_accesses_mvsum-for-damos-region-tracing
+++ a/mm/damon/core.c
@@ -2452,7 +2452,7 @@ static void damos_apply_scheme(struct da
 	struct damos *siter;		/* schemes iterator */
 	unsigned int sidx = 0;
 	struct damon_target *titer;	/* targets iterator */
-	unsigned int tidx = 0;
+	unsigned int tidx = 0, nr_accesses = 0;
 	bool do_trace = false;
 
 	/* get indices for trace_damos_before_apply() */
@@ -2467,6 +2467,7 @@ static void damos_apply_scheme(struct da
 				break;
 			tidx++;
 		}
+		nr_accesses = damon_nr_accesses_mvsum(r, c);
 		do_trace = true;
 	}
 
@@ -2482,7 +2483,7 @@ static void damos_apply_scheme(struct da
 		if (damos_core_filter_out(c, t, r, s))
 			return;
 		ktime_get_coarse_ts64(&begin);
-		trace_damos_before_apply(cidx, sidx, tidx, r,
+		trace_damos_before_apply(cidx, sidx, tidx, r, nr_accesses,
 				damon_nr_regions(t), do_trace);
 		sz_applied = c->ops.apply_scheme(c, t, r, s,
 				&sz_ops_filter_passed);
_

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

mm-damon-sysfs-schemes-fix-dir-put-orders-in-access_pattern_add_dirs.patch
mm-damon-sysfs-schemes-put-stats-for-scheme_add_dirs-internal-error.patch
mm-damon-ops-common-handle-extreme-intervals-in-damon_hot_score.patch
mm-damon-add-a-kernel-doc-comment-for-damon_ctx-probes.patch
mm-damon-add-a-kernel-doc-comment-for-damon_ctx-rnd_state.patch
maintainers-s-seongjae-sj.patch
samples-damon-wsse-handle-damon_start-failure.patch
samples-damon-prcl-handle-damon_start-failure.patch
samples-damon-mtier-handle-damon_start-failure.patch
samples-damon-mtier-handle-damon_stop-failure.patch
samples-damon-wsse-stop-and-free-damon-ctx-when-damon_call-fails.patch
samples-damon-prcl-stop-and-free-damon-ctx-when-damon_call-fails.patch
mm-damon-sysfs-kobject_del-target-normal-context-and-kdamond-dirs.patch
mm-damon-sysfs-kobject_del-region-and-target-error-dirs.patch
mm-damon-sysfs-schemes-kobject_del-scheme-dirs.patch
mm-damon-sysfs-schemes-kobject_del-scheme-region-dirs.patch
mm-damon-sysfs-schemes-kobject_del-scheme-filter-dirs.patch
mm-damon-sysfs-schemes-kobject_del-scheme-quota-goal-dirs.patch
mm-damon-sysfs-schemes-kobject_del-scheme-action-destination-dirs.patch
mm-damon-sysfs-kobject_del-probe-dirs.patch
mm-damon-sysfs-kobject_del-probe-filter-dirs.patch
mm-damon-sysfs-kobject_del-probe-dirs-in-probes_addd_dir-error-path.patch
mm-damon-sysfs-schemes-kobject_del-region-for-populate_region-error.patch
docs-mm-damon-design-update-for-damos_quota_node_eligible_mem_bp.patch
docs-abi-damon-document-probe-files.patch
mm-damon-tests-core-kunit-test-damon_rand.patch
selftests-damon-sysfssh-test-multiple-probe-dirs-creation.patch
selftests-damon-sysfssh-test-coreops_filters-directories.patch
selftests-damon-sysfssh-test-dests-dir.patch
selftests-damon-sysfssh-test-all-files-in-quota-goal-dir.patch
mm-damon-core-reduce-range-setup-in-damon_commit_target_regions.patch
mm-damon-sysfs-split-probe-setup-function-out.patch
mm-damon-sysfs-split-out-filters-setup-function.patch
mm-damon-sysfs-fix-typos-in-probe_addrm_dirs-s-attr-probe.patch
mm-damon-core-introduce-damon_nr_accesses_mvsum.patch
mm-damon-tests-core-kunit-test-damon_mvsum.patch
mm-damon-core-always-update-last_nr_accesses-for-intervals-change.patch
mm-damon-core-handle-unreset-nr_accesses-in-damon_nr_accesses_mvsum.patch
mm-damon-core-use-damon_nr_accesses_mvsum-in-__damos_valid_target.patch
mm-damon-core-use-damon_nr_accesses_mvsum-for-damos-region-tracing.patch
mm-damon-sysfs-schemes-use-damon_nr_accesses_mvsum-for-damo-regions.patch
mm-damon-core-remove-damon_warn_fix_nr_accesses_corruption.patch
mm-damon-core-remove-damon_verify_reset_aggregated.patch
mm-damon-core-remove-damon_verify_merge_regions_of.patch
mm-damon-tests-core-kunit-remove-nr_accesses_bp-setup-and-tests.patch
selftests-damon-drgn_dump_damon_status-do-not-dump-nr_accesses_bp.patch
mm-damon-core-remove-nr_accesses_bp-setups-and-updates.patch
mm-damon-core-remove-attrs-param-from-damon_update_region_access_rate.patch
mm-damon-paddr-remove-attrs-param-from-__damon_pa_check_access.patch
mm-damon-vaddr-remove-attrs-param-from-__damon_va_check_access.patch
mm-damon-core-remove-damon_moving_sum-and-its-unit-test.patch
mm-damon-core-remove-damon_region-nr_accesses_bp.patch