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Diffstat (limited to 'Documentation/admin-guide/mm/damon/reclaim.rst')
| -rw-r--r-- | Documentation/admin-guide/mm/damon/reclaim.rst | 81 |
1 files changed, 72 insertions, 9 deletions
diff --git a/Documentation/admin-guide/mm/damon/reclaim.rst b/Documentation/admin-guide/mm/damon/reclaim.rst index 0af51a9705b1..8eba3da8dcee 100644 --- a/Documentation/admin-guide/mm/damon/reclaim.rst +++ b/Documentation/admin-guide/mm/damon/reclaim.rst @@ -46,13 +46,7 @@ that is built with ``CONFIG_DAMON_RECLAIM=y``. To let sysadmins enable or disable it and tune for the given system, DAMON_RECLAIM utilizes module parameters. That is, you can put ``damon_reclaim.<parameter>=<value>`` on the kernel boot command line or write -proper values to ``/sys/modules/damon_reclaim/parameters/<parameter>`` files. - -Note that the parameter values except ``enabled`` are applied only when -DAMON_RECLAIM starts. Therefore, if you want to apply new parameter values in -runtime and DAMON_RECLAIM is already enabled, you should disable and re-enable -it via ``enabled`` parameter file. Writing of the new values to proper -parameter values should be done before the re-enablement. +proper values to ``/sys/module/damon_reclaim/parameters/<parameter>`` files. Below are the description of each parameter. @@ -66,6 +60,17 @@ Setting it as ``N`` disables DAMON_RECLAIM. Note that DAMON_RECLAIM could do no real monitoring and reclamation due to the watermarks-based activation condition. Refer to below descriptions for the watermarks parameter for this. +commit_inputs +------------- + +Make DAMON_RECLAIM reads the input parameters again, except ``enabled``. + +Input parameters that updated while DAMON_RECLAIM is running are not applied +by default. Once this parameter is set as ``Y``, DAMON_RECLAIM reads values +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. + min_age ------- @@ -112,6 +117,33 @@ milliseconds. 1 second by default. +quota_mem_pressure_us +--------------------- + +Desired level of memory pressure-stall time in microseconds. + +While keeping the caps that set by other quotas, DAMON_RECLAIM automatically +increases and decreases the effective level of the quota aiming this level of +memory pressure is incurred. System-wide ``some`` memory PSI in microseconds +per quota reset interval (``quota_reset_interval_ms``) is collected and +compared to this value to see if the aim is satisfied. Value zero means +disabling this auto-tuning feature. + +Disabled by default. + +quota_autotune_feedback +----------------------- + +User-specifiable feedback for auto-tuning of the effective quota. + +While keeping the caps that set by other quotas, DAMON_RECLAIM automatically +increases and decreases the effective level of the quota aiming receiving this +feedback of value ``10,000`` from the user. DAMON_RECLAIM assumes the feedback +value and the quota are positively proportional. Value zero means disabling +this auto-tuning feature. + +Disabled by default. + wmarks_interval --------------- @@ -200,6 +232,37 @@ 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 +--------- + +Skip anonymous pages reclamation. + +If this parameter is set as ``Y``, DAMON_RECLAIM does not reclaim anonymous +pages. By default, ``N``. + + kdamond_pid ----------- @@ -246,7 +309,7 @@ therefore the free memory rate becomes lower than 20%, it asks DAMON_RECLAIM to do nothing again, so that we can fall back to the LRU-list based page granularity reclamation. :: - # cd /sys/modules/damon_reclaim/parameters + # cd /sys/module/damon_reclaim/parameters # echo 30000000 > min_age # echo $((1 * 1024 * 1024 * 1024)) > quota_sz # echo 1000 > quota_reset_interval_ms @@ -257,4 +320,4 @@ granularity reclamation. :: .. [1] https://research.google/pubs/pub48551/ .. [2] https://lwn.net/Articles/787611/ -.. [3] https://www.kernel.org/doc/html/latest/vm/free_page_reporting.html +.. [3] https://www.kernel.org/doc/html/latest/mm/free_page_reporting.html |