Commit df5ba5be authored by Dan Schatzberg's avatar Dan Schatzberg Committed by Linus Torvalds
Browse files

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: default avatarDan Schatzberg <dschatzberg@fb.com>
Acked-by: default avatarJohannes 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0e94682b

include/linux/psi.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

kernel/cgroup/cgroup.c

+12 −6
Original line number Diff line number Diff line
@@ -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,

kernel/sched/psi.c

+1 −1
Original line number Diff line number Diff line
@@ -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,

};

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