From: SeongJae Park <sjpark@xxxxxxxxx> This commit documents the 'initial_regions' feature. Signed-off-by: SeongJae Park <sjpark@xxxxxxxxx> --- Documentation/admin-guide/mm/damon/usage.rst | 35 ++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/Documentation/admin-guide/mm/damon/usage.rst b/Documentation/admin-guide/mm/damon/usage.rst index 153f07da9368..573fcb4c57a7 100644 --- a/Documentation/admin-guide/mm/damon/usage.rst +++ b/Documentation/admin-guide/mm/damon/usage.rst @@ -315,6 +315,41 @@ 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. +Initial Monitoring Target Regions +--------------------------------- + +In case of the debugfs based 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 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 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
