Due to the lack of ways to synchronously access DAMON internal data, DAMON sysfs interface is using damon_callback hooks with its own synchronization mechanism. The mechanism is built on top of damon_callback hooks in an ineifficient and complicated way. Patch series "mm/damon: replace most damon_callback usages in sysfs with new core functions", which starts with commit e035320fd38e ("mm/damon/sysfs-schemes: remove unnecessary schemes existence check in damon_sysfs_schemes_clear_regions()") introduced two new DAMON kernel API functions that providing the synchronous access, replaced most damon_callback hooks usage in DAMON sysfs interface, and cleaned up unnecessary code. Continue the replacement and cleanup works. Update the last DAMON sysfs's usage of its own synchronization mechanism, namely online DAMON parameters commit, to use damon_call() instead of the damon_callback hooks and the hard-to-maintain own synchronization mechanism. Then remove the no more be used code due to the change, and more unused code that just not yet cleaned up. The first four patches of this series do the replacement. Then, following three patches (patches 5-7) remove the DAMON sysfs interface' own synchronization mechanism and its usages, which is no more be used by anyone due to the first four patches. Finally, six patches (8-13) doing more cleanup of no more valid comment and no more used code follow. SeongJae Park (13): mm/damon/sysfs: validate user inputs from damon_sysfs_commit_input() mm/damon/core: invoke kdamond_call() after merging is done if possible mm/damon/core: make damon_set_attrs() be safe to be called from damon_call() mm/damon/sysfs: handle commit command using damon_call() mm/damon/sysfs: remove damon_sysfs_cmd_request code from damon_sysfs_handle_cmd() mm/damon/sysfs: remove damon_sysfs_cmd_request_callback() and its callers mm/damon/sysfs: remove damon_sysfs_cmd_request and its readers mm/damon/sysfs-schemes: remove obsolete comment for damon_sysfs_schemes_clear_regions() mm/damon: remove damon_callback->private mm/damon: remove ->before_start of damon_callback mm/damon: remove damon_callback->after_sampling mm/damon: remove damon_callback->before_damos_apply mm/damon: remove damon_operations->reset_aggregated include/linux/damon.h | 34 ++------- mm/damon/core.c | 64 ++++++++-------- mm/damon/paddr.c | 1 - mm/damon/sysfs-schemes.c | 1 - mm/damon/sysfs.c | 147 +++++------------------------------- mm/damon/tests/core-kunit.h | 6 +- mm/damon/vaddr.c | 1 - 7 files changed, 61 insertions(+), 193 deletions(-) base-commit: 58f3b385bf3ed67fa989e13620dae8331df515d7 -- 2.39.5