mm-damon-core-stop-ctxs-in-damon_start-before-returning-an-error.patch removed from -mm tree

The quilt patch titled
Subject: mm/damon/core: stop ctxs in damon_start() before returning an error
has been removed from the -mm tree. Its filename was
mm-damon-core-stop-ctxs-in-damon_start-before-returning-an-error.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: stop ctxs in damon_start() before returning an error
Date: Mon, 6 Jul 2026 07:06:16 -0700

Patch series "mm/damon: refactor damon_{start,stop,commit}() for simple error handling".

damon_start() and damon_stop() could leave a few of requested DAMON contexts running when they return an error. damon_commit() failure stops the DAMON context, but in an asynchronous way. Callers should stop the left-over DAMON contexts. It is easy to make mistakes, and indeed a few bugs from such mistakes were found and fixed.

Refactor the core API functions to guarantee contexts are completely stopped under failures. Remove the caller side error handlers that are no longer needed due to the refactoring.

Patches Sequence
================

Patch 1 refactors damon_start() to ensure all contexts are stopped for failures. Patch 2 updates unnecessary damon_start() error handling from mtier sample module.

Patch 3 refactors damon_stop() to always success. Patches 4-6 updates callers (damon_{sysfs,reclaim lru_sort}) to ignore the return value. Patch 7 update damon_stop() return value to void. Patch 8 simplifies damon_stop() error handling in mtier sample module.

Patch 9 refactors damon_call() to return errors only after the context is completely stopped. Patches 10 and 11 remove unnecessary error handlings from callers (wsse and prcl sample modules).

This patch (of 11):

When multiple contexts are passed to damon_start(), the function starts the contexts one by one. If any of the operations fails, it immediately returns an error. Contexts that successfully started before the failure keep running. The caller should catch this and stop the contexts. It is complicated and easy to make mistakes. Stop all contexts in damon_start() under the failures.

---

 mm/damon/core.c |    3 +++
 1 file changed, 3 insertions(+)

@@ -1917,6 +1917,9 @@ int damon_start(struct damon_ctx **ctxs,
 		running_exclusive_ctxs = true;
 	mutex_unlock(&damon_lock);
 
+	if (i != nr_ctxs)
+		damon_stop(ctxs, i);
+
 	return err;
 }
 

_

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