From: Bijan Tabatabai <bijantabatab@xxxxxxxxxx> This patchset adds two DAMON commands, commit_schemes_dests and wait_for_schemes_apply, that I have found useful for using a migrate_hot scheme with migration dests. The commit_schemes_dests command, similar to the existing commit_schemes_quota_goals, is used to commit only the dests fields of schemes. This has a couple of benefits: 1) It is more efficient than recommitting all the DAMON data. 2) Doing a full commit resets the aggregation and ops_update intervals. If a user sends the full commit command frequently (relatively to those intervals) the aggregation and ops_update events will be prevented from triggering. Having a separate commit command side steps this problem. The wait_for_schemes_apply command causes the calling thread to wait until all schemes have been applied. It does this by calling damos_walk() with a NULL walk_fn. This can be useful, for example, if a user wants to know when new scheme parameters they've committed have been applied. Another use case could be if a user wants to record the system state every time a scheme is applied for debuging purposes. The functionality of wait_for_schemes_apply can be achieved with the existing update_schemes_tried_bytes and update_schemes_tried_regions commands. However, having a separate command avoids extra work and makes user intent clearer when used in scripts. The first two patches implement the commit_schemes_dests command. The third patch implements the wait_for_schemes_apply command. The fourth and fifth patches add documentation for these new commands. Bijan Tabatabai (5): mm/damon/core: Add damos_destroy_dests() mm/damon/sysfs: Implement a command to only commit scheme dests mm/damon/sysfs: Implement a command to wait until schemes are applied Docs/ABI/damon: Document new DAMON commands Docs/admin-guide/mm/damon/usage: Document new DAMON commands .../ABI/testing/sysfs-kernel-mm-damon | 21 ++++---- Documentation/admin-guide/mm/damon/usage.rst | 4 ++ include/linux/damon.h | 2 + mm/damon/core.c | 12 +++-- mm/damon/sysfs-common.h | 3 ++ mm/damon/sysfs-schemes.c | 35 ++++++++++-- mm/damon/sysfs.c | 54 +++++++++++++++++++ 7 files changed, 116 insertions(+), 15 deletions(-) -- 2.43.5
