From c31067bf5c8dcb1bc26672d447da3dfbf8bbf5bb Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Mon, 27 Apr 2026 21:29:40 -0700 Subject: [PATCH] mm/damon/core: make charge_addr_from aware of end-address exclusivity commit 5a2d162e22bf33eb89d53e802d0fc1ec422e19b6 upstream. DAMON region end address is exclusive one, but charge_addr_from is assigned assuming the end address is inclusive. As a result, DAMOS action to next up to min_region_sz memory can be skipped. This is quite negligible user impact. But, the bug is a bug that can be very simply fixed. Fix the wrong assignment to respect the exclusiveness of the address. The issue was discovered [1] by Sashiko. Link: https://lore.kernel.org/20260428042942.118230-1-sj@kernel.org Link: https://lore.kernel.org/20260428032324.115663-1-sj@kernel.org [1] Fixes: 50585192bc2e ("mm/damon/schemes: skip already charged targets and regions") Signed-off-by: SeongJae Park Cc: # 5.16.x Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/damon/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/damon/core.c b/mm/damon/core.c index 8e5e3bb835d1..46600265d7ff 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -1003,7 +1003,7 @@ static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t, quota->charged_sz += sz; if (quota->esz && quota->charged_sz >= quota->esz) { quota->charge_target_from = t; - quota->charge_addr_from = r->ar.end + 1; + quota->charge_addr_from = r->ar.end; } } if (s->action != DAMOS_STAT)