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Diffstat (limited to 'Documentation/admin-guide/mm/damon/reclaim.rst')
| -rw-r--r-- | Documentation/admin-guide/mm/damon/reclaim.rst | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/Documentation/admin-guide/mm/damon/reclaim.rst b/Documentation/admin-guide/mm/damon/reclaim.rst index af05ae617018..d7a0225b4950 100644 --- a/Documentation/admin-guide/mm/damon/reclaim.rst +++ b/Documentation/admin-guide/mm/damon/reclaim.rst @@ -71,6 +71,10 @@ of parametrs except ``enabled`` again. Once the re-reading is done, this parameter is set as ``N``. If invalid parameters are found while the re-reading, DAMON_RECLAIM will be disabled. +Once ``Y`` is written to this parameter, the user must not write to any +parameters until reading ``commit_inputs`` again returns ``N``. If users +violate this rule, the kernel may exhibit undefined behavior. + min_age ------- @@ -204,6 +208,10 @@ monitoring. This can be used to set lower-bound of the monitoring quality. But, setting this too high could result in increased monitoring overhead. Please refer to the DAMON documentation (:doc:`usage`) for more detail. +Note that this must be 3 or higher. Please refer to the :ref:`Monitoring +<damon_design_monitoring>` section of the design document for the rationale +behind this lower bound. + max_nr_regions -------------- @@ -232,6 +240,28 @@ The end physical address of memory region that DAMON_RECLAIM will do work against. That is, DAMON_RECLAIM will find cold memory regions in this region and reclaims. By default, biggest System RAM is used as the region. +addr_unit +--------- + +A scale factor for memory addresses and bytes. + +This parameter is for setting and getting the :ref:`address unit +<damon_design_addr_unit>` parameter of the DAMON instance for DAMON_RECLAIM. + +``monitor_region_start`` and ``monitor_region_end`` should be provided in this +unit. For example, let's suppose ``addr_unit``, ``monitor_region_start`` and +``monitor_region_end`` are set as ``1024``, ``0`` and ``10``, respectively. +Then DAMON_RECLAIM will work for 10 KiB length of physical address range that +starts from address zero (``[0 * 1024, 10 * 1024)`` in bytes). + +``bytes_reclaim_tried_regions`` and ``bytes_reclaimed_regions`` are also in +this unit. For example, let's suppose values of ``addr_unit``, +``bytes_reclaim_tried_regions`` and ``bytes_reclaimed_regions`` are ``1024``, +``42``, and ``32``, respectively. Then it means DAMON_RECLAIM tried to reclaim +42 KiB memory and successfully reclaimed 32 KiB memory in total. + +If unsure, use only the default value (``1``) and forget about this. + skip_anon --------- @@ -296,6 +326,11 @@ granularity reclamation. :: # echo 200 > wmarks_low # echo Y > enabled +Note that this module (damon_reclaim) cannot run simultaneously with other +DAMON-based special-purpose modules. Refer to :ref:`DAMON design special +purpose modules exclusivity <damon_design_special_purpose_modules_exclusivity>` +for more details. + .. [1] https://research.google/pubs/pub48551/ .. [2] https://lwn.net/Articles/787611/ .. [3] https://www.kernel.org/doc/html/latest/mm/free_page_reporting.html |