From mboxrd@z Thu Jan 1 00:00:00 1970 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F059DC433EF for ; Fri, 1 Oct 2021 23:33:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DBC5561AD0 for ; Fri, 1 Oct 2021 23:33:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231470AbhJAXfn (ORCPT ); Fri, 1 Oct 2021 19:35:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:44064 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230368AbhJAXfn (ORCPT ); Fri, 1 Oct 2021 19:35:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3BEF961A8E; Fri, 1 Oct 2021 23:33:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1633131238; bh=rN/OtuPdmTfHdxL5Q3n1kKNWLqnEmJ09o6DMW+rn/N8=; h=Date:From:To:Subject:From; b=lddrTpufpcdlzBAgIjtCpw50xtAl6WyxD+9FaBft3C9nd0ug/4EKZonZ6NH+lLcdw QFUPaoKaBqW7BXQenNGDsDKuVKFO5ACFarGsD/PzgaoIao8igQGv8fvTffFALh4fbw e/hP58CSCEmECpKPP+oOLFXV/+bI88faJIljHMw0= Date: Fri, 01 Oct 2021 16:33:57 -0700 From: akpm@linux-foundation.org To: amit@kernel.org, benh@kernel.crashing.org, corbet@lwn.net, david@redhat.com, dwmw@amazon.com, elver@google.com, foersleo@amazon.de, gthelen@google.com, Jonathan.Cameron@huawei.com, markubo@amazon.de, mm-commits@vger.kernel.org, rientjes@google.com, shakeelb@google.com, shuah@kernel.org, sj@kernel.org Subject: + docs-admin-guide-mm-damon-document-damon-based-operation-schemes.patch added to -mm tree Message-ID: <20211001233357.hhyaVG6hl%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: Docs/admin-guide/mm/damon: document DAMON-based Operation Schemes has been added to the -mm tree. Its filename is docs-admin-guide-mm-damon-document-damon-based-operation-schemes.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/docs-admin-guide-mm-damon-document-damon-based-operation-schemes.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/docs-admin-guide-mm-damon-document-damon-based-operation-schemes.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: SeongJae Park Subject: Docs/admin-guide/mm/damon: document DAMON-based Operation Schemes This commit add description of DAMON-based operation schemes in the DAMON documents. Link: https://lkml.kernel.org/r/20211001125604.29660-8-sj@kernel.org Signed-off-by: SeongJae Park Cc: Amit Shah Cc: Benjamin Herrenschmidt Cc: David Hildenbrand Cc: David Rienjes Cc: David Woodhouse Cc: Greg Thelen Cc: Jonathan Cameron Cc: Jonathan Corbet Cc: Leonard Foerster Cc: Marco Elver Cc: Markus Boehme Cc: Shakeel Butt Cc: Shuah Khan Signed-off-by: Andrew Morton --- Documentation/admin-guide/mm/damon/start.rst | 11 +++ Documentation/admin-guide/mm/damon/usage.rst | 51 ++++++++++++++++- 2 files changed, 60 insertions(+), 2 deletions(-) --- a/Documentation/admin-guide/mm/damon/start.rst~docs-admin-guide-mm-damon-document-damon-based-operation-schemes +++ a/Documentation/admin-guide/mm/damon/start.rst @@ -108,6 +108,17 @@ the results as separate image files. :: You can view the visualizations of this example workload at [1]_. Visualizations of other realistic workloads are available at [2]_ [3]_ [4]_. + +Data Access Pattern Aware Memory Management +=========================================== + +Below three commands make every memory region of size >=4K that doesn't +accessed for >=60 seconds in your workload to be swapped out. :: + + $ echo "#min-size max-size min-acc max-acc min-age max-age action" > scheme + $ echo "4K max 0 0 60s max pageout" >> scheme + $ damo schemes -c my_thp_scheme + .. [1] https://damonitor.github.io/doc/html/v17/admin-guide/mm/damon/start.html#visualizing-recorded-patterns .. [2] https://damonitor.github.io/test/result/visual/latest/rec.heatmap.1.png.html .. [3] https://damonitor.github.io/test/result/visual/latest/rec.wss_sz.png.html --- a/Documentation/admin-guide/mm/damon/usage.rst~docs-admin-guide-mm-damon-document-damon-based-operation-schemes +++ a/Documentation/admin-guide/mm/damon/usage.rst @@ -34,8 +34,8 @@ the reason, this document describes only debugfs Interface ================= -DAMON exports three files, ``attrs``, ``target_ids``, and ``monitor_on`` under -its debugfs directory, ``/damon/``. +DAMON exports four files, ``attrs``, ``target_ids``, ``schemes`` and +``monitor_on`` under its debugfs directory, ``/damon/``. Attributes @@ -74,6 +74,53 @@ check it again:: Note that setting the target ids doesn't start the monitoring. +Schemes +------- + +For usual DAMON-based data access aware memory management optimizations, users +would simply want the system to apply a memory management action to a memory +region of a specific size having a specific access frequency for a specific +time. DAMON receives such formalized operation schemes from the user and +applies those to the target processes. It also counts the total number and +size of regions that each scheme is applied. This statistics can be used for +online analysis or tuning of the schemes. + +Users can get and set the schemes by reading from and writing to ``schemes`` +debugfs file. Reading the file also shows the statistics of each scheme. To +the file, each of the schemes should be represented in each line in below form: + + min-size max-size min-acc max-acc min-age max-age action + +Note that the ranges are closed interval. Bytes for the size of regions +(``min-size`` and ``max-size``), number of monitored accesses per aggregate +interval for access frequency (``min-acc`` and ``max-acc``), number of +aggregate intervals for the age of regions (``min-age`` and ``max-age``), and a +predefined integer for memory management actions should be used. The supported +numbers and their meanings are as below. + + - 0: Call ``madvise()`` for the region with ``MADV_WILLNEED`` + - 1: Call ``madvise()`` for the region with ``MADV_COLD`` + - 2: Call ``madvise()`` for the region with ``MADV_PAGEOUT`` + - 3: Call ``madvise()`` for the region with ``MADV_HUGEPAGE`` + - 4: Call ``madvise()`` for the region with ``MADV_NOHUGEPAGE`` + - 5: Do nothing but count the statistics + +You can disable schemes by simply writing an empty string to the file. For +example, below commands applies a scheme saying "If a memory region of size in +[4KiB, 8KiB] is showing accesses per aggregate interval in [0, 5] for aggregate +interval in [10, 20], page out the region", check the entered scheme again, and +finally remove the scheme. :: + + # cd /damon + # echo "4096 8192 0 5 10 20 2" > schemes + # cat schemes + 4096 8192 0 5 10 20 2 0 0 + # echo > schemes + +The last two integers in the 4th line of above example is the total number and +the total size of the regions that the scheme is applied. + + Turning On/Off -------------- _ Patches currently in -mm which might be from sj@kernel.org are maintainers-update-seongjaes-email-address.patch mm-damon-core-print-kdamond-start-log-in-debug-mode-only.patch mm-damon-core-account-age-of-target-regions.patch mm-damon-core-implement-damon-based-operation-schemes-damos.patch mm-damon-vaddr-support-damon-based-operation-schemes.patch mm-damon-dbgfs-support-damon-based-operation-schemes.patch mm-damon-schemes-implement-statistics-feature.patch selftests-damon-add-schemes-debugfs-tests.patch docs-admin-guide-mm-damon-document-damon-based-operation-schemes.patch