From nobody Sun Dec 22 06:23:43 2024 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD31DC433FE for ; Thu, 24 Nov 2022 21:21:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229764AbiKXVVz (ORCPT ); Thu, 24 Nov 2022 16:21:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229645AbiKXVV3 (ORCPT ); Thu, 24 Nov 2022 16:21:29 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B300950E3; Thu, 24 Nov 2022 13:21:28 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id EB52CB828DB; Thu, 24 Nov 2022 21:21:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39D8FC4347C; Thu, 24 Nov 2022 21:21:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1669324885; bh=r1rD9KyNMBqJg8aGe8o3Z8JXG+myDQ882BtgLSHPqNo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qUjgEscQClwo6WemlMmyVkQcyAdOazaD4oNfXaCdV2/UsJsDcRJsDeEGq2OaUHB0Q dZXgZFk9mMS2qVQZEBPnOPMqkJ6eeMeU5XxquL3Mh/lR/iwksqM9Mj2iofHucZwPDQ DhzkcbCF8tsK98kfcM+3CxgJudUlWk4s+59VPkmyRvSbTKFTuQ928ckHt/00s8bCXF Qcb7yPnReQEQNzhEyT0OPXVlsHqal9sqMXP/y5pzAJjcshjaMSy5dBVKU9GTx3+U+3 kameP1nAqmJIXnsz3XobD1ANGRnEHhNf7wOw/vMo5uekrxo2lu9HKwvI0lwgQD8otk mFPTE1n1JQD9A== From: SeongJae Park To: Andrew Morton Cc: Jonathan Corbet , damon@lists.linux.dev, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, SeongJae Park Subject: [RFC PATCH 10/11] Docs/admin-guide/mm/damon/usage: document DAMOS filters of sysfs Date: Thu, 24 Nov 2022 21:21:13 +0000 Message-Id: <20221124212114.136863-11-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221124212114.136863-1-sj@kernel.org> References: <20221124212114.136863-1-sj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Document about the newly added files for DAMOS filters on the DAMON usage document. Signed-off-by: SeongJae Park --- Documentation/admin-guide/mm/damon/usage.rst | 48 +++++++++++++++++++- 1 file changed, 46 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/a= dmin-guide/mm/damon/usage.rst index 1a5b6b71efa1..3d82ca6a17ff 100644 --- a/Documentation/admin-guide/mm/damon/usage.rst +++ b/Documentation/admin-guide/mm/damon/usage.rst @@ -87,6 +87,8 @@ comma (","). :: =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 = quotas/ms,bytes,reset_interval_ms =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 = =E2=94=82 weights/sz_permil,nr_accesses_permil,age_permil =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 = watermarks/metric,interval_us,high,mid,low + =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 = filters/nr_filters + =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 = =E2=94=82 0/type,matching,memcg_id =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 = stats/nr_tried,sz_tried,nr_applied,sz_applied,qt_exceeds =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 = tried_regions/ =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 =E2=94=82 = =E2=94=82 0/start,end,nr_accesses,age @@ -151,6 +153,8 @@ number (``N``) to the file creates the number of child = directories named as moment, only one context per kdamond is supported, so only ``0`` or ``1`` = can be written to the file. =20 +.. _sysfs_contexts: + contexts// ------------- =20 @@ -268,8 +272,8 @@ schemes// ------------ =20 In each scheme directory, five directories (``access_pattern``, ``quotas``, -``watermarks``, ``stats``, and ``tried_regions``) and one file (``action``) -exist. +``watermarks``, ``filters``, ``stats``, and ``tried_regions``) and one file +(``action``) exist. =20 The ``action`` file is for setting and getting what action you want to app= ly to memory regions having specific access pattern of the interest. The keywor= ds @@ -347,6 +351,46 @@ as below. =20 The ``interval`` should written in microseconds unit. =20 +schemes//filters/ +-------------------- + +Users could know something more than the kernel for specific types of memo= ry. +In the case, users could do their own management for the memory and hence +doesn't want DAMOS bothers that. Users could limit DAMOS by setting the a= ccess +pattern of the scheme and/or the monitoring regions for the purpose, but t= hat +can be inefficient in some cases. In such cases, users could set non-acce= ss +pattern driven filters using files in this directory. + +In the beginning, this directory has only one file, ``nr_filters``. Writi= ng a +number (``N``) to the file creates the number of child directories named `= `0`` +to ``N-1``. Each directory represents each filter. The filters are evalu= ated +in the numeric order. + +Each filter directory contains three files, namely ``type``, ``matcing``, = and +``memcg_path``. You can write one of two special keywords, ``anon`` for +anonymous pages, or ``memcg`` for specific memory cgroup filtering. In ca= se of +the memory cgroup filtering, you can specify the memory cgroup of the inte= rest +by writing the path of the memory cgroup from the cgroups mount point to +``memcg_path`` file. You can write ``Y`` or ``N`` to ``matching`` file to +filter out pages that does or does not match to the type, respectively. T= hen, +the scheme's action will not be applied to the pages that specified to be +filtered out. + +For example, below restricts a DAMOS action to be applied to only non-anon= ymous +pages of all memory cgroups except ``/having_care_already``.:: + + # echo 2 > nr_filters + # # filter out anonymous pages + echo anon > 0/type + echo Y > 0/matching + # # further filter out all cgroups except one at '/having_care_already' + echo memcg > 1/type + echo /having_care_already > 1/memcg_path + echo N > 1/matching + +Note that filters could be ignored depend on the running DAMON operations = set +`implementation `. + .. _sysfs_schemes_stats: =20 schemes//stats/ --=20 2.25.1