Commit d740037f authored by Dongsheng Yang's avatar Dongsheng Yang Committed by Ingo Molnar
Browse files

sched/cpuacct: Split usage accounting into user_usage and sys_usage 



Sometimes, cpuacct.usage is not detailed enough to see how much CPU
usage a group had. We want to know how much time it used in user mode
and how much in kernel mode.

This patch introduces more files to give this information:

 # ls /sys/fs/cgroup/cpuacct/cpuacct.usage*
 /sys/fs/cgroup/cpuacct/cpuacct.usage
 /sys/fs/cgroup/cpuacct/cpuacct.usage_percpu
 /sys/fs/cgroup/cpuacct/cpuacct.usage_user
 /sys/fs/cgroup/cpuacct/cpuacct.usage_percpu_user
 /sys/fs/cgroup/cpuacct/cpuacct.usage_sys
 /sys/fs/cgroup/cpuacct/cpuacct.usage_percpu_sys

... while keeping the ABI with the existing counter.

Signed-off-by: default avatarDongsheng Yang <yangds.fnst@cn.fujitsu.com>
[ Ported to newer kernels. ]
Signed-off-by: default avatarZhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/aa171da036b520b51c79549e9b3215d29473f19d.1458635566.git.zhaolei@cn.fujitsu.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 5ca3726a

kernel/sched/cpuacct.c

+113 −27
Original line number Diff line number Diff line
@@ -25,11 +25,22 @@ enum cpuacct_stat_index { 
	CPUACCT_STAT_NSTATS,

};



enum cpuacct_usage_index {

	CPUACCT_USAGE_USER,	/* ... user mode */

	CPUACCT_USAGE_SYSTEM,	/* ... kernel mode */



	CPUACCT_USAGE_NRUSAGE,

};



struct cpuacct_usage {

	u64	usages[CPUACCT_USAGE_NRUSAGE];

};



/* track cpu usage of a group of tasks and its child groups */

struct cpuacct {

	struct cgroup_subsys_state css;

	/* cpuusage holds pointer to a u64-type object on every cpu */

	u64 __percpu *cpuusage;

	struct cpuacct_usage __percpu *cpuusage;

	struct kernel_cpustat __percpu *cpustat;

};
@@ -49,7 +60,7 @@ static inline struct cpuacct *parent_ca(struct cpuacct *ca) 
	return css_ca(ca->css.parent);

}



static DEFINE_PER_CPU(u64, root_cpuacct_cpuusage);

static DEFINE_PER_CPU(struct cpuacct_usage, root_cpuacct_cpuusage);

static struct cpuacct root_cpuacct = {

	.cpustat	= &kernel_cpustat,

	.cpuusage	= &root_cpuacct_cpuusage,
@@ -68,7 +79,7 @@ cpuacct_css_alloc(struct cgroup_subsys_state *parent_css) 
	if (!ca)

		goto out;



	ca->cpuusage = alloc_percpu(u64);

	ca->cpuusage = alloc_percpu(struct cpuacct_usage);

	if (!ca->cpuusage)

		goto out_free_ca;
@@ -96,20 +107,37 @@ static void cpuacct_css_free(struct cgroup_subsys_state *css) 
	kfree(ca);

}



static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)

static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu,

				 enum cpuacct_usage_index index)

{

	u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);

	struct cpuacct_usage *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);

	u64 data;



	/*

	 * We allow index == CPUACCT_USAGE_NRUSAGE here to read

	 * the sum of suages.

	 */

	BUG_ON(index > CPUACCT_USAGE_NRUSAGE);



#ifndef CONFIG_64BIT

	/*

	 * Take rq->lock to make 64-bit read safe on 32-bit platforms.

	 */

	raw_spin_lock_irq(&cpu_rq(cpu)->lock);

	data = *cpuusage;

#endif



	if (index == CPUACCT_USAGE_NRUSAGE) {

		int i = 0;



		data = 0;

		for (i = 0; i < CPUACCT_USAGE_NRUSAGE; i++)

			data += cpuusage->usages[i];

	} else {

		data = cpuusage->usages[index];

	}



#ifndef CONFIG_64BIT

	raw_spin_unlock_irq(&cpu_rq(cpu)->lock);

#else

	data = *cpuusage;

#endif



	return data;
@@ -117,69 +145,103 @@ static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) 


static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)

{

	u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);

	struct cpuacct_usage *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);

	int i;



#ifndef CONFIG_64BIT

	/*

	 * Take rq->lock to make 64-bit write safe on 32-bit platforms.

	 */

	raw_spin_lock_irq(&cpu_rq(cpu)->lock);

	*cpuusage = val;

#endif



	for (i = 0; i < CPUACCT_USAGE_NRUSAGE; i++)

		cpuusage->usages[i] = val;



#ifndef CONFIG_64BIT

	raw_spin_unlock_irq(&cpu_rq(cpu)->lock);

#else

	*cpuusage = val;

#endif

}



/* return total cpu usage (in nanoseconds) of a group */

static u64 cpuusage_read(struct cgroup_subsys_state *css, struct cftype *cft)

static u64 __cpuusage_read(struct cgroup_subsys_state *css,

			   enum cpuacct_usage_index index)

{

	struct cpuacct *ca = css_ca(css);

	u64 totalcpuusage = 0;

	int i;



	for_each_possible_cpu(i)

		totalcpuusage += cpuacct_cpuusage_read(ca, i);

		totalcpuusage += cpuacct_cpuusage_read(ca, i, index);



	return totalcpuusage;

}



static u64 cpuusage_user_read(struct cgroup_subsys_state *css,

			      struct cftype *cft)

{

	return __cpuusage_read(css, CPUACCT_USAGE_USER);

}



static u64 cpuusage_sys_read(struct cgroup_subsys_state *css,

			     struct cftype *cft)

{

	return __cpuusage_read(css, CPUACCT_USAGE_SYSTEM);

}



static u64 cpuusage_read(struct cgroup_subsys_state *css, struct cftype *cft)

{

	return __cpuusage_read(css, CPUACCT_USAGE_NRUSAGE);

}



static int cpuusage_write(struct cgroup_subsys_state *css, struct cftype *cft,

			  u64 val)

{

	struct cpuacct *ca = css_ca(css);

	int err = 0;

	int i;

	int cpu;



	/*

	 * Only allow '0' here to do a reset.

	 */

	if (val) {

		err = -EINVAL;

		goto out;

	}

	if (val)

		return -EINVAL;



	for_each_possible_cpu(i)

		cpuacct_cpuusage_write(ca, i, 0);

	for_each_possible_cpu(cpu)

		cpuacct_cpuusage_write(ca, cpu, 0);



out:

	return err;

	return 0;

}



static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)

static int __cpuacct_percpu_seq_show(struct seq_file *m,

				     enum cpuacct_usage_index index)

{

	struct cpuacct *ca = css_ca(seq_css(m));

	u64 percpu;

	int i;



	for_each_possible_cpu(i) {

		percpu = cpuacct_cpuusage_read(ca, i);

		percpu = cpuacct_cpuusage_read(ca, i, index);

		seq_printf(m, "%llu ", (unsigned long long) percpu);

	}

	seq_printf(m, "\n");

	return 0;

}



static int cpuacct_percpu_user_seq_show(struct seq_file *m, void *V)

{

	return __cpuacct_percpu_seq_show(m, CPUACCT_USAGE_USER);

}



static int cpuacct_percpu_sys_seq_show(struct seq_file *m, void *V)

{

	return __cpuacct_percpu_seq_show(m, CPUACCT_USAGE_SYSTEM);

}



static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)

{

	return __cpuacct_percpu_seq_show(m, CPUACCT_USAGE_NRUSAGE);

}



static const char * const cpuacct_stat_desc[] = {

	[CPUACCT_STAT_USER] = "user",

	[CPUACCT_STAT_SYSTEM] = "system",
@@ -219,10 +281,26 @@ static struct cftype files[] = { 
		.read_u64 = cpuusage_read,

		.write_u64 = cpuusage_write,

	},

	{

		.name = "usage_user",

		.read_u64 = cpuusage_user_read,

	},

	{

		.name = "usage_sys",

		.read_u64 = cpuusage_sys_read,

	},

	{

		.name = "usage_percpu",

		.seq_show = cpuacct_percpu_seq_show,

	},

	{

		.name = "usage_percpu_user",

		.seq_show = cpuacct_percpu_user_seq_show,

	},

	{

		.name = "usage_percpu_sys",

		.seq_show = cpuacct_percpu_sys_seq_show,

	},

	{

		.name = "stat",

		.seq_show = cpuacct_stats_show,
@@ -238,10 +316,18 @@ static struct cftype files[] = { 
void cpuacct_charge(struct task_struct *tsk, u64 cputime)

{

	struct cpuacct *ca;

	int index;



	if (user_mode(task_pt_regs(tsk)))

		index = CPUACCT_USAGE_USER;

	else

		index = CPUACCT_USAGE_SYSTEM;



	rcu_read_lock();



	for (ca = task_ca(tsk); ca; ca = parent_ca(ca))

		*this_cpu_ptr(ca->cpuusage) += cputime;

		this_cpu_ptr(ca->cpuusage)->usages[index] += cputime;



	rcu_read_unlock();

}

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