From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ABED731F992; Tue, 28 Apr 2026 04:29:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777350592; cv=none; b=oG1YBGcXMLp0Q4aTbragM4d2EeKIEX1pzw95lpdYFTnaiUohS4MPA/nNzkK3XfexDTR3mv9dNSOwVVfrvJLMqTMm79vdbC4OzsrFhNJ30+jx4gRisxvHmdrCZ3K5t6jStkcEHqPylLTOP/d9BD60zSic5/b7cgKf8rh+VWjM5dc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777350592; c=relaxed/simple; bh=sdIOuHzeJtaYTP8u5YUojhpsDYOu9rOc+EK4UXxTHwc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Vk8cs4BCvE/A6wed1OVXOsFPoId1Wf3jo3eXGHwij1Yq6YmRy8ng5J7zx7UJymN0e/N7NSipYcQEqBZh9COd/e/LjnCIY8lfepZVkiwEOfeDaMKEcQiFqkO8oW+zjfuRTekbwnZS4G4jgIcIKs+QQPpYm8wm5q6xkIiL423mm4c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TnmVEeVf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TnmVEeVf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE875C2BCAF; Tue, 28 Apr 2026 04:29:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777350592; bh=sdIOuHzeJtaYTP8u5YUojhpsDYOu9rOc+EK4UXxTHwc=; h=From:To:Cc:Subject:Date:From; b=TnmVEeVfdPMWYtEMpVKc4rO5BMoxGjEjOZe3LrCEuY4l4WfQ32Vd3S3bInDxlz2Zn oxWi1aONRu+pSfqpzu+f3HpKbj9exi9PKoCjh37w/vLkFYKhpGQ7paLuojm0M03tcp TzX2cO0QJUkBgtsANS28MED6xeWDnTSPzKZiryzNnMBtMBGXrI/hFl+g6DKrL2Eiyw SE2PQValF7fQ9LwaEaRI4J38kdHGGvkrjc6ilCAX4BFQKL/ombDI5z5ALK2iGMfwTV QPHMVH/2c0HoZepJeNufwnGMG8DgOOSsPMj8MElyvbXpKD0KfCagrEeP+4jyZBF88A WnW1bUp7wNRjg== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , "# 5 . 16 . x" , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH] mm/damon/core: make charge_addr_from aware of end-address exclusivity Date: Mon, 27 Apr 2026 21:29:40 -0700 Message-ID: <20260428042942.118230-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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. [1] https://lore.kernel.org/20260428032324.115663-1-sj@kernel.org Fixes: 50585192bc2e ("mm/damon/schemes: skip already charged targets and regions") Cc: # 5.16.x Signed-off-by: SeongJae Park --- 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 278594847cf94..37c9a40d0577b 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -2107,7 +2107,7 @@ static void damos_apply_scheme(struct damon_ctx *c, struct damon_target *t, if (damos_quota_is_set(quota) && 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) base-commit: 986c714ac6faa9750e15ccaec72ff2823c96a5c6 -- 2.47.3