github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-28 10:09:10 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

Docs/mm/damon/design: document fail_charge_{num,denom}

Browse Source 
Update DAMON design document for the DAMOS action failed region quota
charge ratio.

Link: https://lore.kernel.org/20260428013402.115171-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
SeongJae Park 2026-04-27 18:33:54 -07:00 committed by Andrew Morton
parent fad1124120
commit 776270536d
1 changed files with 22 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
Documentation/mm/damon/design.rst
View File

@ -565,6 +565,28 @@ interface <sysfs_interface>`, refer to :ref:`weights <sysfs_quotas>` part of
the documentation.
.. _damon_design_damos_quotas_failed_memory_charging_ratio:
Action-failed Memory Charging Ratio
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
DAMOS action to a given region can fail for some subsets of the memory of the
region. For example, if the action is ``pageout`` and the region has some
unreclaimable pages, applying the action to the pages will fail. The amount of
system resource that is taken for such failed action applications is usually
different from that for successful action applications. For such cases, users
can set different charging ratio for such failed memory. The ratio can be
specified using ``fail_charge_num`` and ``fail_charge_denom`` parameters. The
two parameters represent the numerator and denominator of the ratio. The
feature is enabled only if ``fail_charge_denom`` is not zero.
For example, let's suppose a DAMOS action is applied to a region of 1,000 MiB
size. The action is successfully applied to only 700 MiB of the region.
``fail_charge_num`` and ``fail_charge_denom`` are set to ``1`` and ``1024``,
respectively. Then only 700 MiB and 300 KiB of size (``700 MiB + 300 MiB * 1 /
1024``) will be charged.
.. _damon_design_damos_quotas_auto_tuning:
Aim-oriented Feedback-driven Auto-tuning