diff options
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 5 | ||||
| -rw-r--r-- | kernel/cgroup/pids.c | 89 |
2 files changed, 76 insertions, 18 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index c8390baef90b..f886c6ad704e 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -2220,6 +2220,11 @@ PID Interface Files The number of times the cgroup's total number of processes hit the pids.max limit (see also pids_localevents). + pids.events.local + Similar to pids.events but the fields in the file are local + to the cgroup i.e. not hierarchical. The file modified event + generated on this file reflects only the local events. + Organisational operations are not blocked by cgroup policies, so it is possible to have pids.current > pids.max. This can be done by either setting the limit to be smaller than pids.current, or attaching enough diff --git a/kernel/cgroup/pids.c b/kernel/cgroup/pids.c index c09b744d548c..f5cb0ec45b9d 100644 --- a/kernel/cgroup/pids.c +++ b/kernel/cgroup/pids.c @@ -57,10 +57,12 @@ struct pids_cgroup { atomic64_t limit; int64_t watermark; - /* Handle for "pids.events" */ + /* Handles for pids.events[.local] */ struct cgroup_file events_file; + struct cgroup_file events_local_file; atomic64_t events[NR_PIDCG_EVENTS]; + atomic64_t events_local[NR_PIDCG_EVENTS]; }; static struct pids_cgroup *css_pids(struct cgroup_subsys_state *css) @@ -244,21 +246,23 @@ static void pids_event(struct pids_cgroup *pids_forking, struct pids_cgroup *p = pids_forking; bool limit = false; - for (; parent_pids(p); p = parent_pids(p)) { - /* Only log the first time limit is hit. */ - if (atomic64_inc_return(&p->events[PIDCG_FORKFAIL]) == 1) { - pr_info("cgroup: fork rejected by pids controller in "); - pr_cont_cgroup_path(p->css.cgroup); - pr_cont("\n"); - } - cgroup_file_notify(&p->events_file); - - if (!cgroup_subsys_on_dfl(pids_cgrp_subsys) || - cgrp_dfl_root.flags & CGRP_ROOT_PIDS_LOCAL_EVENTS) - break; + /* Only log the first time limit is hit. */ + if (atomic64_inc_return(&p->events_local[PIDCG_FORKFAIL]) == 1) { + pr_info("cgroup: fork rejected by pids controller in "); + pr_cont_cgroup_path(p->css.cgroup); + pr_cont("\n"); + } + cgroup_file_notify(&p->events_local_file); + if (!cgroup_subsys_on_dfl(pids_cgrp_subsys) || + cgrp_dfl_root.flags & CGRP_ROOT_PIDS_LOCAL_EVENTS) + return; - if (p == pids_over_limit) + for (; parent_pids(p); p = parent_pids(p)) { + if (p == pids_over_limit) { limit = true; + atomic64_inc(&p->events_local[PIDCG_MAX]); + cgroup_file_notify(&p->events_local_file); + } if (limit) atomic64_inc(&p->events[PIDCG_MAX]); @@ -368,16 +372,32 @@ static s64 pids_peak_read(struct cgroup_subsys_state *css, return READ_ONCE(pids->watermark); } -static int pids_events_show(struct seq_file *sf, void *v) +static int __pids_events_show(struct seq_file *sf, bool local) { struct pids_cgroup *pids = css_pids(seq_css(sf)); enum pidcg_event pe = PIDCG_MAX; + atomic64_t *events; if (!cgroup_subsys_on_dfl(pids_cgrp_subsys) || - cgrp_dfl_root.flags & CGRP_ROOT_PIDS_LOCAL_EVENTS) + cgrp_dfl_root.flags & CGRP_ROOT_PIDS_LOCAL_EVENTS) { pe = PIDCG_FORKFAIL; + local = true; + } + events = local ? pids->events_local : pids->events; - seq_printf(sf, "max %lld\n", (s64)atomic64_read(&pids->events[pe])); + seq_printf(sf, "max %lld\n", (s64)atomic64_read(&events[pe])); + return 0; +} + +static int pids_events_show(struct seq_file *sf, void *v) +{ + __pids_events_show(sf, false); + return 0; +} + +static int pids_events_local_show(struct seq_file *sf, void *v) +{ + __pids_events_show(sf, true); return 0; } @@ -404,9 +424,42 @@ static struct cftype pids_files[] = { .file_offset = offsetof(struct pids_cgroup, events_file), .flags = CFTYPE_NOT_ON_ROOT, }, + { + .name = "events.local", + .seq_show = pids_events_local_show, + .file_offset = offsetof(struct pids_cgroup, events_local_file), + .flags = CFTYPE_NOT_ON_ROOT, + }, + { } /* terminate */ +}; + +static struct cftype pids_files_legacy[] = { + { + .name = "max", + .write = pids_max_write, + .seq_show = pids_max_show, + .flags = CFTYPE_NOT_ON_ROOT, + }, + { + .name = "current", + .read_s64 = pids_current_read, + .flags = CFTYPE_NOT_ON_ROOT, + }, + { + .name = "peak", + .flags = CFTYPE_NOT_ON_ROOT, + .read_s64 = pids_peak_read, + }, + { + .name = "events", + .seq_show = pids_events_show, + .file_offset = offsetof(struct pids_cgroup, events_file), + .flags = CFTYPE_NOT_ON_ROOT, + }, { } /* terminate */ }; + struct cgroup_subsys pids_cgrp_subsys = { .css_alloc = pids_css_alloc, .css_free = pids_css_free, @@ -415,7 +468,7 @@ struct cgroup_subsys pids_cgrp_subsys = { .can_fork = pids_can_fork, .cancel_fork = pids_cancel_fork, .release = pids_release, - .legacy_cftypes = pids_files, + .legacy_cftypes = pids_files_legacy, .dfl_cftypes = pids_files, .threaded = true, }; |