Re: [PATCH 5/5] cgroup: Defer kill_css_finish() in cgroup_apply_control_disable()

[Bert Karwatzki]

Am Sonntag, dem 31.05.2026 um 20:45 +0200 schrieb Bert Karwatzki:
> 
> The test that hang when running
> # LTPROOT=/home/bert/ltp-install/ ./kirk --run-suite controllers
> is always  cgroup_fj_function_net_prio.
> Also when bisecting this I disabled (i.e. commented out) the
> memcg_stress test in ~/ltp-install/runtest/controllers as it takes a lot of
> time (30min) and succeeds even in the version where hangs occur.
> 
> Bert Karwatzki

I've done more testing and found that running the
cgroup_fj_function_net_prio test alone gives no hang, the hang
only occurs when other tests are run before it:

Suite: controllers
──────────────────
cgroup_core01: pass  (0.026s)
cgroup_core02: pass  (0.004s)
cgroup_core03: pass  (0.005s)
cgroup: fail  (2m 41s)
memcg_regression: skip  (3.558s)
memcg_test_3: pass  (0.112s)
memcg_failcnt: skip  (0.027s)
memcg_force_empty: skip  (0.016s)
memcg_limit_in_bytes: skip  (0.015s)
memcg_stat_rss: skip  (0.015s)
memcg_subgroup_charge: skip  (0.015s)
memcg_max_usage_in_bytes: skip  (0.014s)
memcg_move_charge_at_immigrate: skip  (0.015s)
memcg_memsw_limit_in_bytes: skip  (0.015s)
memcg_stat: skip  (0.014s)
memcg_use_hierarchy: skip  (0.015s)
memcg_usage_in_bytes: skip  (0.014s)
memcg_control: pass  (6.046s)
memcontrol01: pass  (0.004s)
memcontrol02: pass  (0.628s)
memcontrol03: pass  (16.009s)
memcontrol04: pass  (0.926s)
cgroup_fj_function_debug: skip  (0.012s)
cgroup_fj_function_cpuset: skip  (0.037s)
cgroup_fj_function_cpu: skip  (0.055s)
cgroup_fj_function_cpuacct: pass  (0.046s)
cgroup_fj_function_memory: skip  (0.035s)
cgroup_fj_function_freezer: pass  (0.044s)
cgroup_fj_function_devices: pass  (0.067s)
cgroup_fj_function_blkio: skip  (0.010s)
cgroup_fj_function_net_cls: pass  (0.055s)
cgroup_fj_function_perf_event: pass  (0.063s)
cgroup_fj_function_net_prio: HANG 

I tried to narrow down this list and found that a hang occurs
int the net_prio test only if the perf_event test is run before it:

cgroup_fj_function_perf_event: pass  (0.063s)
cgroup_fj_function_net_prio: HANG


Bert Karwatzki