mm-damon-core-cleanup-targets-and-regions-at-once-on-kdamond-termination.patch removed from -mm tree

The quilt patch titled
Subject: mm/damon/core: cleanup targets and regions at once on kdamond termination
has been removed from the -mm tree. Its filename was
mm-damon-core-cleanup-targets-and-regions-at-once-on-kdamond-termination.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: SeongJae Park <[email protected]>
Subject: mm/damon/core: cleanup targets and regions at once on kdamond termination
Date: Sat, 17 Jan 2026 09:52:49 -0800

When kdamond terminates, it destroys the regions of the context first, and the targets of the context just before the kdamond main function returns. Because regions are linked inside targets, doing them separately is only inefficient and looks weird. A more serious problem is that the cleanup of the targets is done after damon_ctx->kdamond reset, which is the event that lets DAMON API callers know the kdamond is no longer actively running. That is, some DAMON targets could still exist while kdamond is not running. There are no real problems from this, but this implicit fact could cause subtle racy issues in future. Destroy targets and regions at one.

Adding contexts on how the code has evolved in the way. Doing only regions destruction was because putting pids of the targets were done on DAMON API callers. Commit 7114bc5e01cf ("mm/damon/core: add cleanup_target() ops callback") moved the role to be done via operations set on each target destruction. Hence it removed the reason to do only regions cleanup. Commit 3a69f1635769 ("mm/damon/core: destroy targets when kdamond_fn() finish") therefore further destructed targets on kdamond termination time. It was still separated from regions destruction because damon_operations->cleanup() may do additional targets cleanup. Placing the targets destruction after damon_ctx->kdamond reset was just an unnecessary decision of the commit. The previous commit removed damon_operations->cleanup(), so there is no more reason to do destructions of regions and targets separately.

---

 mm/damon/core.c |    8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

@@ -2748,8 +2748,6 @@ static void kdamond_init_ctx(struct damo
 static int kdamond_fn(void *data)
 {
 	struct damon_ctx *ctx = data;
-	struct damon_target *t;
-	struct damon_region *r, *next;
 	unsigned int max_nr_accesses = 0;
 	unsigned long sz_limit = 0;
 

@@ -2854,10 +2852,7 @@ static int kdamond_fn(void *data)
 		}
 	}
 done:
-	damon_for_each_target(t, ctx) {
-		damon_for_each_region_safe(r, next, t)
-			damon_destroy_region(r, t);
-	}
+	damon_destroy_targets(ctx);
 
 	kfree(ctx->regions_score_histogram);
 	kdamond_call(ctx, true);

@@ -2875,7 +2870,6 @@ done:
 		running_exclusive_ctxs = false;
 	mutex_unlock(&damon_lock);
 
-	damon_destroy_targets(ctx);
 	return 0;
 }
 

_

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