From nobody Thu Apr 9 10:52:51 2026 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 546C537F8C4; Wed, 4 Mar 2026 04:41:29 +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=1772599289; cv=none; b=Wr2xMkxvBSO9lFVj4OVukX46UBbvqQW33JS+nX2YJ16Nqn9bs7JVMZJXScRRNUuQTVF3/xct21RQMdfHnhhe4RSP7i2niubg6OyVJZT5Ug22/209SqsYXfsFm7hCpMbxuF9U4CJtcZ+/IKpm2N90wHHAcll+OzmGWMmk/0xl1co= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772599289; c=relaxed/simple; bh=BRPVQ//gFwEK7BX6XnTBEauvn4um7HRHs55ygHmJ5MY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VV7C18uF21JCnqVJhdG7puu2wD3WO+cZYdOQ/00V2gum2qzvSYYAvYThCwQRLASyx/5tLaB9XS5gedJGuvPkEqhjK3K7i7wBly0m9OONUjCO8vgYGOAL9jWq0MVde0v8gyTRSVppsI9EB331M9WnS/KtjCTTfP83QKERFqlY5x4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=drGqn8oa; 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="drGqn8oa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5912C2BCAF; Wed, 4 Mar 2026 04:41:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772599289; bh=BRPVQ//gFwEK7BX6XnTBEauvn4um7HRHs55ygHmJ5MY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=drGqn8oasNMPpRGlhAVrnnqVCuASZrV5LJe28KZ7+yMqDFjIfwo3qSejyNL+lvPck 8nuOYiRbROexyxJYKh4PbkVpIpcPyPwuoYLupU9EhZ7uqocsHsmMEhWn6VfWaGQwOT pBgRSbF2r1ZonJCXHSJn0bMHnOPSGtJDzlgA3iLhyfxFb/8sTrBaByila6IXVC4QzE Tcvm9sRda6B2KP0ywrJh7QdzdVvE3tP7ai4oSIStmu2d4geB22MXDbcw78VC1Uow2/ NHUeVU68Qk8AsGzbkszZfUbqTqkf7ZQU/pTP9mIewE092cN7/fg1d/KGitPokgStKx 66e6IhuPilUdw== From: SeongJae Park To: Cc: SeongJae Park , "Liam R. Howlett" , Andrew Morton , David Hildenbrand , Jonathan Corbet , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Shuah Khan , Suren Baghdasaryan , Vlastimil Babka , damon@lists.linux.dev, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v2 05/10] Docs/mm/damon/design: document the goal-based quota tuner selections Date: Tue, 3 Mar 2026 20:41:14 -0800 Message-ID: <20260304044122.79394-6-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260304044122.79394-1-sj@kernel.org> References: <20260304044122.79394-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Update the design document for the newly added goal-based quota tuner selection feature. Signed-off-by: SeongJae Park --- Documentation/mm/damon/design.rst | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/des= ign.rst index dd64f5d7f3193..28d932ceaf7ed 100644 --- a/Documentation/mm/damon/design.rst +++ b/Documentation/mm/damon/design.rst @@ -564,6 +564,18 @@ aggressiveness (the quota) of the corresponding scheme= . For example, if DAMOS is under achieving the goal, DAMOS automatically increases the quota. If = DAMOS is over achieving the goal, it decreases the quota. =20 +There are two such tuning algorithms that users can select as they need. + +- ``consist``: A proportional feedback loop based algorithm. Tries to fin= d an + optimum quota that should be consistently kept, to keep achieving the go= al. + Useful for kernel-only operation on dynamic and long-running environment= s. + This is the default selection. If unsure, use this. +- ``temporal``: More straightforward algorithm. Tries to achieve the goal= as + fast as possible, using maximum allowed quota, but only for a temporal s= hort + time. When the quota is under-achieved, this algorithm keeps tuning quo= ta to + a maximum allowed one. Once the quota is [over]-achieved, this sets the + quota zero. Useful for deterministic control required environments. + The goal can be specified with five parameters, namely ``target_metric``, ``target_value``, ``current_value``, ``nid`` and ``path``. The auto-tuning mechanism tries to make ``current_value`` of ``target_metric`` be same to --=20 2.47.3