From: SeongJae Park <sjpark@amazon.com>
To: <akpm@linux-foundation.org>
Cc: SeongJae Park <sjpark@amazon.de>, <Jonathan.Cameron@Huawei.com>,
<aarcange@redhat.com>, <acme@kernel.org>,
<alexander.shishkin@linux.intel.com>, <amit@kernel.org>,
<benh@kernel.crashing.org>, <brendan.d.gregg@gmail.com>,
<brendanhiggins@google.com>, <cai@lca.pw>,
<colin.king@canonical.com>, <corbet@lwn.net>, <dwmw@amazon.com>,
<foersleo@amazon.de>, <irogers@google.com>, <jolsa@redhat.com>,
<kirill@shutemov.name>, <mark.rutland@arm.com>, <mgorman@suse.de>,
<minchan@kernel.org>, <mingo@redhat.com>, <namhyung@kernel.org>,
<peterz@infradead.org>, <rdunlap@infradead.org>,
<riel@surriel.com>, <rientjes@google.com>, <rostedt@goodmis.org>,
<sblbir@amazon.com>, <shakeelb@google.com>, <shuah@kernel.org>,
<sj38.park@gmail.com>, <snu@amazon.de>, <vbabka@suse.cz>,
<vdavydov.dev@gmail.com>, <yang.shi@linux.alibaba.com>,
<ying.huang@intel.com>, <linux-damon@amazon.com>,
<linux-mm@kvack.org>, <linux-doc@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: [RFC v2 9/9] Docs/damon: Document physical memory monitoring support
Date: Wed, 3 Jun 2020 16:11:35 +0200 [thread overview]
Message-ID: <20200603141135.10575-10-sjpark@amazon.com> (raw)
In-Reply-To: <20200603141135.10575-1-sjpark@amazon.com>
From: SeongJae Park <sjpark@amazon.de>
This commit adds description for the physical memory monitoring usage in
the DAMON document.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
Documentation/admin-guide/mm/damon/usage.rst | 42 ++++++++++++++------
1 file changed, 29 insertions(+), 13 deletions(-)
diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst
index 137ed770c2d6..359745f0dbfb 100644
--- a/Documentation/admin-guide/mm/damon/usage.rst
+++ b/Documentation/admin-guide/mm/damon/usage.rst
@@ -314,27 +314,42 @@ check it again::
Target PIDs
-----------
-Users can get and set the pids of monitoring target processes by reading from
-and writing to the ``pids`` file. For example, below commands set processes
-having pids 42 and 4242 as the processes to be monitored and check it again::
+To monitor the virtual memory address spaces of specific processes, users can
+get and set the pids of monitoring target processes by reading from and writing
+to the ``pids`` file. For example, below commands set processes having pids 42
+and 4242 as the processes to be monitored and check it again::
# cd <debugfs>/damon
# echo 42 4242 > pids
# cat pids
42 4242
+Users can also monitor the physical memory address space of the system by
+writing a special keyword, "``paddr\n``" to the file. In this case, reading the
+file will show ``-1``, as below::
+
+ # cd <debugfs>/damon
+ # echo paddr > pids
+ # cat pids
+ -1
+
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 case of the virtual memory monitoring, 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 contrast, DAMON do not automatically sets and updates the monitoring target
+regions in case of physical memory monitoring. Therefore, users should set the
+monitoring target regions by themselves.
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
@@ -354,10 +369,11 @@ region of process 42, and another couple of address ranges, ``20-40`` and
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.
+Note that this sets the initial monitoring target regions only. In case of
+virtual memory monitoring, DAMON will automatically updates the boundary of the
+regions after one ``regions update interval``. Therefore, users should set the
+``regions update interval`` large enough in this case, if they don't want the
+update.
Record
--
2.17.1
prev parent reply other threads:[~2020-06-03 14:16 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-03 14:11 [RFC v2 0/9] DAMON: Support Access Monitoring of Any Address Space Including Physical Memory SeongJae Park
2020-06-03 14:11 ` [RFC v2 1/9] mm/damon: Use vm-independent address range concept SeongJae Park
2020-06-03 14:11 ` [RFC v2 2/9] mm/damon: Clean up code using 'struct damon_addr_range' SeongJae Park
2020-06-03 14:11 ` [RFC v2 3/9] mm/damon: Make monitoring target regions init/update configurable SeongJae Park
2020-06-03 14:11 ` [RFC v2 4/9] mm/damon/debugfs: Allow users to set initial monitoring target regions SeongJae Park
2020-06-03 14:11 ` [RFC v2 5/9] Docs/damon: Document 'initial_regions' feature SeongJae Park
2020-06-03 14:11 ` [RFC v2 6/9] mm/damon: Make access check primitive configurable SeongJae Park
2020-06-03 14:11 ` [RFC v2 7/9] mm/damon: Implement callbacks for physical memory monitoring SeongJae Park
2020-06-03 16:09 ` David Hildenbrand
2020-06-04 7:26 ` SeongJae Park
2020-06-04 14:58 ` David Hildenbrand
2020-06-04 15:23 ` SeongJae Park
2020-06-04 15:39 ` David Hildenbrand
2020-06-04 15:51 ` SeongJae Park
2020-06-04 16:01 ` David Hildenbrand
2020-06-03 14:11 ` [RFC v2 8/9] mm/damon/debugfs: Support " SeongJae Park
2020-06-03 14:11 ` SeongJae Park [this message]
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