diff options
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 9 | ||||
| -rw-r--r-- | include/linux/misc_cgroup.h | 2 | ||||
| -rw-r--r-- | kernel/cgroup/misc.c | 41 |
3 files changed, 52 insertions, 0 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 2e4e74bea6ef..52763d6b2919 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -2642,6 +2642,15 @@ Miscellaneous controller provides 3 interface files. If two misc resources (res_ res_a 3 res_b 0 + misc.peak + A read-only flat-keyed file shown in all cgroups. It shows the + historical maximum usage of the resources in the cgroup and its + children.:: + + $ cat misc.peak + res_a 10 + res_b 8 + misc.max A read-write flat-keyed file shown in the non root cgroups. Allowed maximum usage of the resources in the cgroup and its children.:: diff --git a/include/linux/misc_cgroup.h b/include/linux/misc_cgroup.h index d70eab2501ee..618392d41975 100644 --- a/include/linux/misc_cgroup.h +++ b/include/linux/misc_cgroup.h @@ -31,11 +31,13 @@ struct misc_cg; /** * struct misc_res: Per cgroup per misc type resource * @max: Maximum limit on the resource. + * @watermark: Historical maximum usage of the resource. * @usage: Current usage of the resource. * @events: Number of times, the resource limit exceeded. */ struct misc_res { u64 max; + atomic64_t watermark; atomic64_t usage; atomic64_t events; }; diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c index 79a3717a5803..b92daf5d234d 100644 --- a/kernel/cgroup/misc.c +++ b/kernel/cgroup/misc.c @@ -121,6 +121,19 @@ static void misc_cg_cancel_charge(enum misc_res_type type, struct misc_cg *cg, misc_res_name[type]); } +static void misc_cg_update_watermark(struct misc_res *res, u64 new_usage) +{ + u64 old; + + while (true) { + old = atomic64_read(&res->watermark); + if (new_usage <= old) + break; + if (atomic64_cmpxchg(&res->watermark, old, new_usage) == old) + break; + } +} + /** * misc_cg_try_charge() - Try charging the misc cgroup. * @type: Misc res type to charge. @@ -159,6 +172,7 @@ int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, u64 amount) ret = -EBUSY; goto err_charge; } + misc_cg_update_watermark(res, new_usage); } return 0; @@ -308,6 +322,29 @@ static int misc_cg_current_show(struct seq_file *sf, void *v) } /** + * misc_cg_peak_show() - Show the peak usage of the misc cgroup. + * @sf: Interface file + * @v: Arguments passed + * + * Context: Any context. + * Return: 0 to denote successful print. + */ +static int misc_cg_peak_show(struct seq_file *sf, void *v) +{ + int i; + u64 watermark; + struct misc_cg *cg = css_misc(seq_css(sf)); + + for (i = 0; i < MISC_CG_RES_TYPES; i++) { + watermark = atomic64_read(&cg->res[i].watermark); + if (READ_ONCE(misc_res_capacity[i]) || watermark) + seq_printf(sf, "%s %llu\n", misc_res_name[i], watermark); + } + + return 0; +} + +/** * misc_cg_capacity_show() - Show the total capacity of misc res on the host. * @sf: Interface file * @v: Arguments passed @@ -358,6 +395,10 @@ static struct cftype misc_cg_files[] = { .seq_show = misc_cg_current_show, }, { + .name = "peak", + .seq_show = misc_cg_peak_show, + }, + { .name = "capacity", .seq_show = misc_cg_capacity_show, .flags = CFTYPE_ONLY_ON_ROOT, |