Changes from RFC v2 (https://lore.kernel.org/r/20240311204545.47097-1-sj@xxxxxxxxxx) - Add documentation - Add Tested-by: Honggyu Kim <honggyu.kim@xxxxxx> - Wordsmith commit messages Changes from RFC v1 (https://lore.kernel.org/r/20240307030013.47041-1-sj@xxxxxxxxxx) - Mark the folio as old if it was young - Rename __damon_pa_young() to damon_folio_young_one() DAMON provides its best-effort accuracy-overhead tradeoff under the user-defined ranges of acceptable level of the monitoring accuracy and overhead. A recent discussion for tiered memory management support from DAMON[1] concluded that finding memory regions of specific access pattern with low overhead despite of low accuracy via DAMON first, and then double checking the access of the region again in a finer (e.g., page) granularity could be a useful strategy for some DAMOS schemes. Add a new type of DAMOS filter, namely 'young' for such a case. It checks each page of DAMOS target region is accessed since the last check, and filters it out or in if 'matching' parameter is 'true' or 'false', respectively. Because this is a filter type that applied in page granularity, the support depends on DAMON operations set, similar to 'anon' and 'memcg' DAMOS filter types. Implement the support on the DAMON operations set for the physical address space, 'paddr', since one of the expected usages[1] is based on the physical address space. [1] https://lore.kernel.org/r/20240227235121.153277-1-sj@xxxxxxxxxx SeongJae Park (7): mm/damon/paddr: implement damon_folio_young() mm/damon/paddr: implement damon_folio_mkold() mm/damon: add DAMOS filter type YOUNG mm/damon/paddr: implement DAMOS filter type YOUNG Docs/mm/damon/design: document 'young page' type DAMOS filter Docs/admin-guide/mm/damon/usage: update for young page type DAMOS filter Docs/ABI/damon: update for 'youg page' type DAMOS filter .../ABI/testing/sysfs-kernel-mm-damon | 6 +- Documentation/admin-guide/mm/damon/usage.rst | 26 ++++---- Documentation/mm/damon/design.rst | 20 +++--- include/linux/damon.h | 2 + mm/damon/paddr.c | 64 ++++++++++++------- mm/damon/sysfs-schemes.c | 1 + 6 files changed, 70 insertions(+), 49 deletions(-) base-commit: 4b4dd809460911d6c406bb45d2c627a9e5734468 -- 2.39.2
