DAMON users can retrieve the monitoring results via 'after_aggregation' callbacks if the user is using the kernel API, or 'damon_aggregated' tracepoint if the user is in the user space. Those are useful if full monitoring results are necessary. However, if the user has interest in only some regions having specific access pattern, the interfaces could be inefficient. For example, some DAMOS users might want to know exactly what regions were identified as fulfilling the access pattern of the scheme, for a debugging or a tuning. This patchset implements DAMON kernel API callbacks and sysfs directory for efficient exposure of the information. The new callback will be called for each region before specific DAMOS action is gonna tried to be applied. The sysfs directory will be called 'tried_regions' and placed under each scheme sysfs directory. User can write a special keyworkd, 'update_schemes_regions' to the 'state' file of a kdamond sysfs directory. Then, DAMON sysfs interface will fill the directory with the information of regions that corresponding scheme action was tried to be applied for one aggregation interval. Patches Sequence ---------------- First five patches (1-5) clean up and refactor code that following patch will touch, and the following one (patch 6) implements the DAMON callback for DAMON kernel API users. Following six patches (7-12) clean up and refactor the sysfs interface before the new sysfs directory introduction. Following two patches (13 and 14) implement the sysfs directories, and successing two patches (15 and 16) implement the special keyword for 'state' to fill and clean up the directories. Finally, two more patches (17 and 18) for the documentation of the usage and ABI follow. Assembled Tree -------------- This patchset is based on the latest mm-unstable tree[1]. Assembled tree is also available at the damon/next tree[2]. [1] https://git.kernel.org/akpm/mm/h/mm-unstable [2] https://git.kernel.org/sj/h/damon/next SeongJae Park (18): mm/damon/modules: deduplicate init steps for DAMON context setup mm/damon/core: split out DAMOS-charged region skip logic into a new function mm/damon/core: split damos application logic into a new function mm/damon/core: split out scheme stat update logic into a new function mm/damon/core: split out scheme quota adjustment logic into a new function mm/damon/core: add a DAMON callback for scheme target regions check mm/damon/sysfs: Use damon_addr_range for regions' start and end values mm/damon/sysfs: remove parameters of damon_sysfs_region_alloc() mm/damon/sysfs: move sysfs_lock to common module mm/damon/sysfs: move unsigned long range directory to common module mm/damon/sysfs: split out kdamond-independent schemes stats update logic into a new function mm/damon/sysfs: move schemes directory implementation to separate module mm/damon/sysfs-schemes: implement schemes/tried_regions directory mm/damon/sysfs-schemes: implement scheme region directory mm/damon/sysfs: implement DAMOS-tried regions update command mm/damon/sysfs-schemes: implement DAMOS tried regions clear command Docs/admin-guide/mm/damon/usage: document schemes/<s>/tried_regions directory Docs/ABI/damon: document 'schemes/<s>/tried_regions' directory .../ABI/testing/sysfs-kernel-mm-damon | 32 + Documentation/admin-guide/mm/damon/usage.rst | 44 +- include/linux/damon.h | 5 + mm/damon/Makefile | 6 +- mm/damon/core.c | 259 ++-- mm/damon/lru_sort.c | 17 +- mm/damon/modules-common.c | 42 + mm/damon/modules-common.h | 3 + mm/damon/reclaim.c | 17 +- mm/damon/sysfs-common.c | 107 ++ mm/damon/sysfs-common.h | 56 + mm/damon/sysfs-schemes.c | 1281 +++++++++++++++++ mm/damon/sysfs.c | 1224 ++-------------- 13 files changed, 1813 insertions(+), 1280 deletions(-) create mode 100644 mm/damon/modules-common.c create mode 100644 mm/damon/sysfs-common.c create mode 100644 mm/damon/sysfs-common.h create mode 100644 mm/damon/sysfs-schemes.c -- 2.25.1
