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cgroup/misc: Introduce misc.events.local

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Currently the event counting provided by misc.events is hierarchical,
it's not practical if user is only concerned with events of a
specified cgroup. Therefore, introduce misc.events.local collect events
specific to the given cgroup.

This is analogous to memory.events.local and pids.events.local.

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Xiu Jianfeng 2024-07-11 10:14:57 +00:00 committed by Tejun Heo
parent b824766504
commit 6a26f9c689
3 changed files with 41 additions and 6 deletions
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5
Documentation/admin-guide/cgroup-v2.rst
View File

@ -2680,6 +2680,11 @@ Miscellaneous controller provides 3 interface files. If two misc resources (res_
The number of times the cgroup's resource usage was
about to go over the max boundary.
misc.events.local
Similar to misc.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.
Migration and Ownership
~~~~~~~~~~~~~~~~~~~~~~~

3
include/linux/misc_cgroup.h
View File

@ -40,6 +40,7 @@ struct misc_res {
atomic64_t watermark;
atomic64_t usage;
atomic64_t events;
atomic64_t events_local;
};
/**
@ -53,6 +54,8 @@ struct misc_cg {
/* misc.events */
struct cgroup_file events_file;
/* misc.events.local */
struct cgroup_file events_local_file;
struct misc_res res[MISC_CG_RES_TYPES];
};

39
kernel/cgroup/misc.c
View File

@ -134,6 +134,17 @@ static void misc_cg_update_watermark(struct misc_res *res, u64 new_usage)
}
}
static void misc_cg_event(enum misc_res_type type, struct misc_cg *cg)
{
atomic64_inc(&cg->res[type].events_local);
cgroup_file_notify(&cg->events_local_file);
for (; parent_misc(cg); cg = parent_misc(cg)) {
atomic64_inc(&cg->res[type].events);
cgroup_file_notify(&cg->events_file);
}
}
/**
* misc_cg_try_charge() - Try charging the misc cgroup.
* @type: Misc res type to charge.
@ -177,10 +188,7 @@ int misc_cg_try_charge(enum misc_res_type type, struct misc_cg *cg, u64 amount)
return 0;
err_charge:
for (j = i; j; j = parent_misc(j)) {
atomic64_inc(&j->res[type].events);
cgroup_file_notify(&j->events_file);
}
misc_cg_event(type, i);
for (j = cg; j != i; j = parent_misc(j))
misc_cg_cancel_charge(type, j, amount);
@ -368,20 +376,33 @@ 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)
static int __misc_events_show(struct seq_file *sf, bool local)
{
struct misc_cg *cg = css_misc(seq_css(sf));
u64 events;
int i;
for (i = 0; i < MISC_CG_RES_TYPES; i++) {
events = atomic64_read(&cg->res[i].events);
if (local)
events = atomic64_read(&cg->res[i].events_local);
else
events = atomic64_read(&cg->res[i].events);
if (READ_ONCE(misc_res_capacity[i]) || events)
seq_printf(sf, "%s.max %llu\n", misc_res_name[i], events);
}
return 0;
}
static int misc_events_show(struct seq_file *sf, void *v)
{
return __misc_events_show(sf, false);
}
static int misc_events_local_show(struct seq_file *sf, void *v)
{
return __misc_events_show(sf, true);
}
/* Misc cgroup interface files */
static struct cftype misc_cg_files[] = {
{
@ -409,6 +430,12 @@ static struct cftype misc_cg_files[] = {
.file_offset = offsetof(struct misc_cg, events_file),
.seq_show = misc_events_show,
},
{
.name = "events.local",
.flags = CFTYPE_NOT_ON_ROOT,
.file_offset = offsetof(struct misc_cg, events_local_file),
.seq_show = misc_events_local_show,
},
{}
};