[RFC PATCH 1/6] mm/damon/core: handle invalid target in damos_fix_stale_charge_pointers()

[SJ Park <sj@kernel.org>]

The fixup of DAMOS quota charge pointers
(damos->charge_{target,addr}_from) for removed targets and regions is
done in damos_fix_stale_charge_pointers().  A similar fixup for invalid
(terminated pid) targets is done in kdamond_apply_schemes().  Having
similar fixups in different places only make it confusing to read the
code.  Consolidate the fixups into damos_fix_stale_charge_pointers().

Signed-off-by: SJ Park <sj@kernel.org>
---
 mm/damon/core.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/mm/damon/core.c b/mm/damon/core.c
index 73b571b429cb3..ce75db510a9d3 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -3394,7 +3394,11 @@ static void damos_fix_stale_charge_pointers(struct damon_ctx *c,
 		return;
 	damon_for_each_target(t, c) {
 		if (t == quota->charge_target_from) {
-			if (damon_nr_regions(t) > 0)
+			bool valid_target = true;
+
+			if (c->ops.target_valid && !c->ops.target_valid(t))
+				valid_target = false;
+			if (valid_target && damon_nr_regions(t) > 0)
 				return;
 			break;
 		}
@@ -3513,15 +3517,8 @@ static noinline_for_stack void kdamond_apply_schemes(struct damon_ctx *c)
 	max_region_sz = damon_region_sz_limit(c);
 	mutex_lock(&c->walk_control_lock);
 	damon_for_each_target(t, c) {
-		if (c->ops.target_valid && c->ops.target_valid(t) == false) {
-			damon_for_each_scheme(s, c) {
-				if (s->quota.charge_target_from != t)
-					continue;
-				s->quota.charge_target_from = NULL;
-				s->quota.charge_addr_from = 0;
-			}
+		if (c->ops.target_valid && c->ops.target_valid(t) == false)
 			continue;
-		}
 		damos_apply_target(c, t, max_region_sz);
 	}
 
-- 
2.47.3