linux-kernel - [RFC v2 5/9] Docs/damon: Document 'initial

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200603141135.10575-6-sjpark@amazon.com>
Date:   Wed, 3 Jun 2020 16:11:31 +0200
From:   SeongJae Park <sjpark@...zon.com>
To:     <akpm@...ux-foundation.org>
CC:     SeongJae Park <sjpark@...zon.de>, <Jonathan.Cameron@...wei.com>,
        <aarcange@...hat.com>, <acme@...nel.org>,
        <alexander.shishkin@...ux.intel.com>, <amit@...nel.org>,
        <benh@...nel.crashing.org>, <brendan.d.gregg@...il.com>,
        <brendanhiggins@...gle.com>, <cai@....pw>,
        <colin.king@...onical.com>, <corbet@....net>, <dwmw@...zon.com>,
        <foersleo@...zon.de>, <irogers@...gle.com>, <jolsa@...hat.com>,
        <kirill@...temov.name>, <mark.rutland@....com>, <mgorman@...e.de>,
        <minchan@...nel.org>, <mingo@...hat.com>, <namhyung@...nel.org>,
        <peterz@...radead.org>, <rdunlap@...radead.org>,
        <riel@...riel.com>, <rientjes@...gle.com>, <rostedt@...dmis.org>,
        <sblbir@...zon.com>, <shakeelb@...gle.com>, <shuah@...nel.org>,
        <sj38.park@...il.com>, <snu@...zon.de>, <vbabka@...e.cz>,
        <vdavydov.dev@...il.com>, <yang.shi@...ux.alibaba.com>,
        <ying.huang@...el.com>, <linux-damon@...zon.com>,
        <linux-mm@...ck.org>, <linux-doc@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: [RFC v2 5/9] Docs/damon: Document 'initial_regions' feature

From: SeongJae Park <sjpark@...zon.de>

This commit documents the 'initial_regions' feature.

Signed-off-by: SeongJae Park <sjpark@...zon.de>
---
 Documentation/admin-guide/mm/damon/usage.rst | 34 ++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst
index 18a19c35b4f3..137ed770c2d6 100644
--- a/Documentation/admin-guide/mm/damon/usage.rst
+++ b/Documentation/admin-guide/mm/damon/usage.rst
@@ -326,6 +326,40 @@ having pids 42 and 4242 as the processes to be monitored and check it again::
 Note that setting the pids doesn't start the monitoring.
 
 
+Initla Monitoring Target Regions
+--------------------------------
+
+DAMON automatically sets and updates the monitoring target regions so that
+entire memory mappings of target processes can be covered.  However, users
+might want to limit the monitoring region to specific address ranges, such as
+the heap, the stack, or specific file-mapped area.  Or, some users might know
+the initial access pattern of their workloads and therefore want to set optimal
+initial regions for the 'adaptive regions adjustment'.
+
+In such cases, users can explicitly set the initial monitoring target regions
+as they want, by writing proper values to the ``init_regions`` file.  Each line
+of the input should represent one region in below form.::
+
+    <pid> <start address> <end address>
+
+The ``pid`` should be already in ``pids`` file, and the regions should be
+passed in address order.  For example, below commands will set a couple of
+address ranges, ``1-100`` and ``100-200`` as the initial monitoring target
+region of process 42, and another couple of address ranges, ``20-40`` and
+``50-100`` as that of process 4242.::
+
+    # cd <debugfs>/damon
+    # echo "42   1       100
+            42   100     200
+            4242 20      40
+            4242 50      100" > init_regions
+
+Note that this sets the initial monitoring target regions only.  DAMON will
+automatically updates the boundary of the regions after one ``regions update
+interval``.  Therefore, users should set the ``regions update interval`` large
+enough.
+
+
 Record
 ------
 
-- 
2.17.1