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 47BDF58ABE; Mon, 19 Feb 2024 19:44:47 +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=1708371888; cv=none; b=NdWgradMnkSZpbcJ1n/LaJ8cg0viuIkhMat+PscEV7XqUEtNH5ilHmSfJYXxw0JbaqFIxthemUL5xMEiRJgTQG13eYyOAaLoC4uCph2kBd3rcOebOWIpnx6ph+sXD8bIIeBgtrLTSq/FOZP3i2G3IgDDVV+AcpVlQKo30H+YCqE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708371888; c=relaxed/simple; bh=dE+jqLZYW9QB5NiFklbDnZHaYSFDuOnT6wibaYvQ7fQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=V6CSpID45oPoL3UOUAIop8LyyzyOjdCMwgItGP8u7CaMmoh/AOBivPmYqFPOydJRZovqLJhcOuFR8Odon7OzQhsCKst0S4YELVZcGULNKASK1/ByvfMuwtSm0rYxEHou4bJVqgTLIeBhyeUnlPUyCc5REKIjnSJdgEmjQURtwgE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rN+wAd4r; 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="rN+wAd4r" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A133C43399; Mon, 19 Feb 2024 19:44:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708371887; bh=dE+jqLZYW9QB5NiFklbDnZHaYSFDuOnT6wibaYvQ7fQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rN+wAd4rUpHbmoSCSt+/pVijeH1M2J+z3ioq9IiqpMA7SQFSRjct47t4BrxCbYLzm g+NTWKrJdapNMH3m9ClPNCicsC8FXavIYUJ+PTZpM3XOUKOjufVIRPa+f6MVCL8FKx mnvvP4UR8ztDA3EZAIC758uAZSZn6xL0EAMZAUfFtGXapQSihyvtpmetzNaC/Kghcx UNloo8Ow4xzXJiJmt/6CbhAsy17pIVqzgkj0XUIKlijM/hF+Tkk2+/az2jLdwG67tG ZGw7C9Tdx2lPuF00Kfz/OfYDrG79xQFFIGBkn/Tpc1eB2mhLP1THJX3eXJLAQ/kPEA eQzcGIUVQS9rA== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , Jonathan Corbet , damon@lists.linux.dev, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 15/20] Docs/mm/damon/design: document quota goal self-tuning Date: Mon, 19 Feb 2024 11:44:26 -0800 Message-Id: <20240219194431.159606-16-sj@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240219194431.159606-1-sj@kernel.org> References: <20240219194431.159606-1-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: 8bit update DAMON design doc to explain the quota goal self-tuning, which can be used by setting the goal's metric to metrics that kernel can self-retrieve. Signed-off-by: SeongJae Park --- Documentation/mm/damon/design.rst | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst index 2bd0c203dcfb..8c89d26f0baa 100644 --- a/Documentation/mm/damon/design.rst +++ b/Documentation/mm/damon/design.rst @@ -398,12 +398,28 @@ Aim-oriented Feedback-driven Auto-tuning ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Automatic feedback-driven quota tuning. Instead of setting the absolute quota -value, users can repeatedly provide numbers representing how much of their goal -for the scheme is achieved as feedback. DAMOS then automatically tunes the +value, users can specify the metric of their interest, and what target value +they want the metric value to be. DAMOS then automatically tunes the 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. +The goal can be specified with three parameters, namely ``target_metric``, +``target_value``, and ``current_value``. The auto-tuning mechanism tries to +make ``current_value`` of ``target_metric`` be same to ``target_value``. +Currently, two ``target_metric`` are provided. + +- ``user_input``: User-provided value. Users could use any metric that they + has interest in for the value. Use space main workload's latency or + throughput, system metrics like free memory ratio or memory pressure stall + time (PSI) could be examples. Note that users should explicitly set + ``current_value`` on their own in this case. In other words, users should + repeatedly provide the feedback. +- ``some_mem_psi_us``: System-wide ``some`` memory pressure stall information + in microseconds that measured from last quota reset to next quota reset. + DAMOS does the measurement on its own, so only ``target_value`` need to be + set by users at the initial time. In other words, DAMOS does self-feedback. + .. _damon_design_damos_watermarks: -- 2.39.2