kernel/sched/psi.c: expose pressure metrics on root cgroup

Pressure metrics are already recorded and exposed in procfs for the
entire system, but any tool which monitors cgroup pressure has to
special case the root cgroup to read from procfs.  This patch exposes
the already recorded pressure metrics on the root cgroup.

Link: http://lkml.kernel.org/r/20190510174938.3361741-1-dschatzberg@fb.com
Signed-off-by: Dan Schatzberg <dschatzberg@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Dan Schatzberg 2019-05-14 15:41:18 -07:00 committed by Linus Torvalds
parent 0e94682b73
commit df5ba5be74
3 changed files with 14 additions and 7 deletions

View file

@ -12,6 +12,7 @@ struct css_set;
#ifdef CONFIG_PSI
extern struct static_key_false psi_disabled;
extern struct psi_group psi_system;
void psi_init(void);

View file

@ -3540,15 +3540,24 @@ static int cpu_stat_show(struct seq_file *seq, void *v)
#ifdef CONFIG_PSI
static int cgroup_io_pressure_show(struct seq_file *seq, void *v)
{
return psi_show(seq, &seq_css(seq)->cgroup->psi, PSI_IO);
struct cgroup *cgroup = seq_css(seq)->cgroup;
struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi;
return psi_show(seq, psi, PSI_IO);
}
static int cgroup_memory_pressure_show(struct seq_file *seq, void *v)
{
return psi_show(seq, &seq_css(seq)->cgroup->psi, PSI_MEM);
struct cgroup *cgroup = seq_css(seq)->cgroup;
struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi;
return psi_show(seq, psi, PSI_MEM);
}
static int cgroup_cpu_pressure_show(struct seq_file *seq, void *v)
{
return psi_show(seq, &seq_css(seq)->cgroup->psi, PSI_CPU);
struct cgroup *cgroup = seq_css(seq)->cgroup;
struct psi_group *psi = cgroup->id == 1 ? &psi_system : &cgroup->psi;
return psi_show(seq, psi, PSI_CPU);
}
static ssize_t cgroup_pressure_write(struct kernfs_open_file *of, char *buf,
@ -4801,7 +4810,6 @@ static struct cftype cgroup_base_files[] = {
#ifdef CONFIG_PSI
{
.name = "io.pressure",
.flags = CFTYPE_NOT_ON_ROOT,
.seq_show = cgroup_io_pressure_show,
.write = cgroup_io_pressure_write,
.poll = cgroup_pressure_poll,
@ -4809,7 +4817,6 @@ static struct cftype cgroup_base_files[] = {
},
{
.name = "memory.pressure",
.flags = CFTYPE_NOT_ON_ROOT,
.seq_show = cgroup_memory_pressure_show,
.write = cgroup_memory_pressure_write,
.poll = cgroup_pressure_poll,
@ -4817,7 +4824,6 @@ static struct cftype cgroup_base_files[] = {
},
{
.name = "cpu.pressure",
.flags = CFTYPE_NOT_ON_ROOT,
.seq_show = cgroup_cpu_pressure_show,
.write = cgroup_cpu_pressure_write,
.poll = cgroup_pressure_poll,

View file

@ -173,7 +173,7 @@ static u64 psi_period __read_mostly;
/* System-level pressure and stall tracking */
static DEFINE_PER_CPU(struct psi_group_cpu, system_group_pcpu);
static struct psi_group psi_system = {
struct psi_group psi_system = {
.pcpu = &system_group_pcpu,
};