The series consists of two parts:
- pids.events rework (originally v2, patches 1-6,
- migration charging, patches 7-9.
The changes are independent in principle, I stacked them for (my)
convenience and because they both deserve RFC:
1) Changed semantics of v2 pids.events
- similar change was proposed for memory.swap.events:max [1]
2) Migration charging is obsolete concept
How are the new events supposed to be useful?
- pids.events.local:max
- tells that cgroup's limit is hit (too tight?)
- pids.events.local:max.imposed
- tells that cgroup's workload was restricted (generalization of
'cgroup: fork rejected by pids controller in %s' message)
- pids.events:*
- "only" directs top-down search to cgroups of interest
The migration charging is motivated by apparenty surprising
pids.current > pids.max
because supervised processes are forked in supervisor's cgroup (more
details in commit cgroup/pids: Enforce pids.max on task migrations too)
Changes from v2 (https://lore.kernel.org/r/20200205134426.10570-1-mkoutny@xxxxxxxx)
- implemented pids.events.local (Tejun)
- added migration charging
[1] https://lore.kernel.org/r/20230202155626.1829121-1-hannes@xxxxxxxxxxx/
Michal Koutný (9):
cgroup/pids: Remove superfluous zeroing
cgroup/pids: Separate semantics of pids.events related to pids.max
cgroup/pids: Make event counters hierarchical
cgroup/pids: Add pids.events.local
selftests: cgroup: Lexicographic order in Makefile
selftests: cgroup: Add basic tests for pids controller
cgroup/pids: Replace uncharge/charge pair with a single function
cgroup/pids: Enforce pids.max on task migrations
selftests: cgroup: Add tests pids controller
Documentation/admin-guide/cgroup-v1/pids.rst | 3 +-
Documentation/admin-guide/cgroup-v2.rst | 22 +-
include/linux/cgroup-defs.h | 7 +-
kernel/cgroup/cgroup.c | 16 +-
kernel/cgroup/pids.c | 206 +++++++++----
tools/testing/selftests/cgroup/Makefile | 25 +-
tools/testing/selftests/cgroup/test_pids.c | 302 +++++++++++++++++++
7 files changed, 514 insertions(+), 67 deletions(-)
create mode 100644 tools/testing/selftests/cgroup/test_pids.c
base-commit: 026e680b0a08a62b1d948e5a8ca78700bfac0e6e
--
2.44.0
