On Tue, Sep 14, 2021 at 7:18 PM brookxu <brookxu.cn@xxxxxxxxx> wrote:
>
> From: Chunguang Xu <brookxu@xxxxxxxxxxx>
>
> Introduce misc.events to make it easier for us to understand
> the pressure of resources. Currently only the 'max' event is
> implemented, which indicates the times the resource is about
> to exceeds the max limit.
>
> Signed-off-by: Chunguang Xu <brookxu@xxxxxxxxxxx>
> ---
>
> v3: remove misc.events.local.
> v2: remove cgroup v1 files.
>
> include/linux/misc_cgroup.h | 5 +++++
> kernel/cgroup/misc.c | 24 ++++++++++++++++++++++++
> 2 files changed, 29 insertions(+)
>
> diff --git a/include/linux/misc_cgroup.h b/include/linux/misc_cgroup.h
> index da2367e..091f2d2 100644
> --- a/include/linux/misc_cgroup.h
> +++ b/include/linux/misc_cgroup.h
> @@ -36,6 +36,7 @@ enum misc_res_type {
> struct misc_res {
> unsigned long max;
> atomic_long_t usage;
> + atomic_long_t events;
> bool failed;
> };
>
> @@ -46,6 +47,10 @@ struct misc_res {
> */
> struct misc_cg {
> struct cgroup_subsys_state css;
> +
> + /* misc.events */
> + struct cgroup_file events_file;
> +
> struct misc_res res[MISC_CG_RES_TYPES];
> };
>
> diff --git a/kernel/cgroup/misc.c b/kernel/cgroup/misc.c
> index ec02d96..4b2b492 100644
> --- a/kernel/cgroup/misc.c
> +++ b/kernel/cgroup/misc.c
> @@ -171,6 +171,11 @@ int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg,
> return 0;
>
> err_charge:
> + for (j = i; j; j = parent_misc(j)) {
> + atomic_long_inc(&j->res[type].events);
> + cgroup_file_notify(&j->events_file);
> + }
> +
> for (j = cg; j != i; j = parent_misc(j))
> misc_cg_cancel_charge(type, j, amount);
> misc_cg_cancel_charge(type, i, amount);
> @@ -335,6 +340,19 @@ static int misc_cg_capacity_show(struct seq_file *sf, void *v)
> return 0;
> }
>
> +static int misc_events_show(struct seq_file *sf, void *v)
> +{
> + struct misc_cg *cg = css_misc(seq_css(sf));
> + unsigned long events, i;
> +
> + for (i = 0; i < MISC_CG_RES_TYPES; i++) {
> + events = atomic_long_read(&cg->res[i].events);
> + if (READ_ONCE(misc_res_capacity[i]) || events)
> + seq_printf(sf, "%s.max %lu\n", misc_res_name[i], events);
> + }
> + return 0;
> +}
> +
> /* Misc cgroup interface files */
> static struct cftype misc_cg_files[] = {
> {
> @@ -353,6 +371,12 @@ static int misc_cg_capacity_show(struct seq_file *sf, void *v)
> .seq_show = misc_cg_capacity_show,
> .flags = CFTYPE_ONLY_ON_ROOT,
> },
> + {
> + .name = "events",
> + .flags = CFTYPE_NOT_ON_ROOT,
> + .file_offset = offsetof(struct misc_cg, events_file),
> + .seq_show = misc_events_show,
> + },
> {}
> };
>
> --
> 1.8.3.1
>
Reviewed-by: Vipin Sharma <vipinsh@xxxxxxxxxx>
