diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-26 14:34:17 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-26 14:34:17 -0700 |
commit | b55b048718c8c833186c87ceeea86b78346cda2e (patch) | |
tree | 073dd3a3aa3ccb439f467de421a6c59f95c92b79 /kernel/cgroup_pids.c | |
parent | bbce2ad2d711c12d93145a7bbdf086e73f414bcd (diff) | |
parent | 55094f57535831883b60776de5eb78c6bfb3c16d (diff) | |
download | linux-b55b048718c8c833186c87ceeea86b78346cda2e.tar.bz2 |
Merge branch 'for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
"Nothing too exciting.
- updates to the pids controller so that pid limit breaches can be
noticed and monitored from userland.
- cleanups and non-critical bug fixes"
* 'for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: remove duplicated include from cgroup.c
cgroup: Use lld instead of ld when printing pids controller events_limit
cgroup: Add pids controller event when fork fails because of pid limit
cgroup: allow NULL return from ss->css_alloc()
cgroup: remove unnecessary 0 check from css_from_id()
cgroup: fix idr leak for the first cgroup root
Diffstat (limited to 'kernel/cgroup_pids.c')
-rw-r--r-- | kernel/cgroup_pids.c | 34 |
1 files changed, 33 insertions, 1 deletions
diff --git a/kernel/cgroup_pids.c b/kernel/cgroup_pids.c index 303097b37429..2bd673783f1a 100644 --- a/kernel/cgroup_pids.c +++ b/kernel/cgroup_pids.c @@ -49,6 +49,12 @@ struct pids_cgroup { */ atomic64_t counter; int64_t limit; + + /* Handle for "pids.events" */ + struct cgroup_file events_file; + + /* Number of times fork failed because limit was hit. */ + atomic64_t events_limit; }; static struct pids_cgroup *css_pids(struct cgroup_subsys_state *css) @@ -72,6 +78,7 @@ pids_css_alloc(struct cgroup_subsys_state *parent) pids->limit = PIDS_MAX; atomic64_set(&pids->counter, 0); + atomic64_set(&pids->events_limit, 0); return &pids->css; } @@ -213,10 +220,21 @@ static int pids_can_fork(struct task_struct *task) { struct cgroup_subsys_state *css; struct pids_cgroup *pids; + int err; css = task_css_check(current, pids_cgrp_id, true); pids = css_pids(css); - return pids_try_charge(pids, 1); + err = pids_try_charge(pids, 1); + if (err) { + /* Only log the first time events_limit is incremented. */ + if (atomic64_inc_return(&pids->events_limit) == 1) { + pr_info("cgroup: fork rejected by pids controller in "); + pr_cont_cgroup_path(task_cgroup(current, pids_cgrp_id)); + pr_cont("\n"); + } + cgroup_file_notify(&pids->events_file); + } + return err; } static void pids_cancel_fork(struct task_struct *task) @@ -288,6 +306,14 @@ static s64 pids_current_read(struct cgroup_subsys_state *css, return atomic64_read(&pids->counter); } +static int pids_events_show(struct seq_file *sf, void *v) +{ + struct pids_cgroup *pids = css_pids(seq_css(sf)); + + seq_printf(sf, "max %lld\n", (s64)atomic64_read(&pids->events_limit)); + return 0; +} + static struct cftype pids_files[] = { { .name = "max", @@ -300,6 +326,12 @@ static struct cftype pids_files[] = { .read_s64 = pids_current_read, .flags = CFTYPE_NOT_ON_ROOT, }, + { + .name = "events", + .seq_show = pids_events_show, + .file_offset = offsetof(struct pids_cgroup, events_file), + .flags = CFTYPE_NOT_ON_ROOT, + }, { } /* terminate */ }; |