[PATCH v2 0/3] cpuacct: Show all detail stats in one file

[PATCH v2 0/3] cpuacct: Show all detail stats in one file

[Zhao Lei]

In current code, we can get cpuacct data from severial files,
but each file have its lilmit.

For example:
we can get cpu usage in user and kernel mode by cpuacct.stat,
but we can't get detail data of each cpu in above file.
we can get each cpu's kernel mode usage in cpuacct.usage_percpu_sys,
but we can't get user mode data in the same time.

This patch introduce cpuacct.usage_all, to show all detailed
cpu accounting data altogether:
 # cat cpuacct.usage_all
 cpu user system
 0 3809760299 5807968992
 1 3250329855 454612211
 ..

Any aspects of statistics data can be get from this file
with a simple data-processing code.

Changelog v1->v2:
 1: Rewrite subject and changelog to fix typos and
    make it more accurate.
 2: Use a variable for the cpustat array itself to make
    code clean(avoid lot of 'kcpustat->').
 3: Add missed newline between variable definitions and
    the first non-definition C statement.
 Above are suggested by: Ingo Molnar <mingo.kernel.org@gmail.com>
 4: Remove '[]' in CPUID, to make it easier to parse.
 Suggested by: Peter Zijlstra <peterz@infradead.org>

Zhao Lei (3):
  cpuacct: Merge cpuacct_usage_index and cpuacct_stat_index
  cpuacct: Use loop to avoid copies of the similar code in
    cpuacct_stats_show()
  cpuacct: Show all detail stats in one file

 kernel/sched/cpuacct.c | 114 +++++++++++++++++++++++++++++++------------------
 1 file changed, 73 insertions(+), 41 deletions(-)

-- 
1.8.5.1

[PATCH v2 1/3] cpuacct: Merge cpuacct_usage_index and cpuacct_stat_index

[Zhao Lei]

These two types have similar function.
No need to separate them.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
---
 kernel/sched/cpuacct.c | 47 ++++++++++++++++++++---------------------------
 1 file changed, 20 insertions(+), 27 deletions(-)

diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 41f85c4..74241eb 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -25,15 +25,13 @@ enum cpuacct_stat_index {
 	CPUACCT_STAT_NSTATS,
 };
 
-enum cpuacct_usage_index {
-	CPUACCT_USAGE_USER,	/* ... user mode */
-	CPUACCT_USAGE_SYSTEM,	/* ... kernel mode */
-
-	CPUACCT_USAGE_NRUSAGE,
+static const char * const cpuacct_stat_desc[] = {
+	[CPUACCT_STAT_USER] = "user",
+	[CPUACCT_STAT_SYSTEM] = "system",
 };
 
 struct cpuacct_usage {
-	u64	usages[CPUACCT_USAGE_NRUSAGE];
+	u64	usages[CPUACCT_STAT_NSTATS];
 };
 
 /* track cpu usage of a group of tasks and its child groups */
@@ -108,16 +106,16 @@ static void cpuacct_css_free(struct cgroup_subsys_state *css)
 }
 
 static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu,
-				 enum cpuacct_usage_index index)
+				 enum cpuacct_stat_index index)
 {
 	struct cpuacct_usage *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
 	u64 data;
 
 	/*
-	 * We allow index == CPUACCT_USAGE_NRUSAGE here to read
+	 * We allow index == CPUACCT_STAT_NSTATS here to read
 	 * the sum of suages.
 	 */
-	BUG_ON(index > CPUACCT_USAGE_NRUSAGE);
+	BUG_ON(index > CPUACCT_STAT_NSTATS);
 
 #ifndef CONFIG_64BIT
 	/*
@@ -126,11 +124,11 @@ static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu,
 	raw_spin_lock_irq(&cpu_rq(cpu)->lock);
 #endif
 
-	if (index == CPUACCT_USAGE_NRUSAGE) {
+	if (index == CPUACCT_STAT_NSTATS) {
 		int i = 0;
 
 		data = 0;
-		for (i = 0; i < CPUACCT_USAGE_NRUSAGE; i++)
+		for (i = 0; i < CPUACCT_STAT_NSTATS; i++)
 			data += cpuusage->usages[i];
 	} else {
 		data = cpuusage->usages[index];
@@ -155,7 +153,7 @@ static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
 	raw_spin_lock_irq(&cpu_rq(cpu)->lock);
 #endif
 
-	for (i = 0; i < CPUACCT_USAGE_NRUSAGE; i++)
+	for (i = 0; i < CPUACCT_STAT_NSTATS; i++)
 		cpuusage->usages[i] = val;
 
 #ifndef CONFIG_64BIT
@@ -165,7 +163,7 @@ static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
 
 /* return total cpu usage (in nanoseconds) of a group */
 static u64 __cpuusage_read(struct cgroup_subsys_state *css,
-			   enum cpuacct_usage_index index)
+			   enum cpuacct_stat_index index)
 {
 	struct cpuacct *ca = css_ca(css);
 	u64 totalcpuusage = 0;
@@ -180,18 +178,18 @@ static u64 __cpuusage_read(struct cgroup_subsys_state *css,
 static u64 cpuusage_user_read(struct cgroup_subsys_state *css,
 			      struct cftype *cft)
 {
-	return __cpuusage_read(css, CPUACCT_USAGE_USER);
+	return __cpuusage_read(css, CPUACCT_STAT_USER);
 }
 
 static u64 cpuusage_sys_read(struct cgroup_subsys_state *css,
 			     struct cftype *cft)
 {
-	return __cpuusage_read(css, CPUACCT_USAGE_SYSTEM);
+	return __cpuusage_read(css, CPUACCT_STAT_SYSTEM);
 }
 
 static u64 cpuusage_read(struct cgroup_subsys_state *css, struct cftype *cft)
 {
-	return __cpuusage_read(css, CPUACCT_USAGE_NRUSAGE);
+	return __cpuusage_read(css, CPUACCT_STAT_NSTATS);
 }
 
 static int cpuusage_write(struct cgroup_subsys_state *css, struct cftype *cft,
@@ -213,7 +211,7 @@ static int cpuusage_write(struct cgroup_subsys_state *css, struct cftype *cft,
 }
 
 static int __cpuacct_percpu_seq_show(struct seq_file *m,
-				     enum cpuacct_usage_index index)
+				     enum cpuacct_stat_index index)
 {
 	struct cpuacct *ca = css_ca(seq_css(m));
 	u64 percpu;
@@ -229,24 +227,19 @@ static int __cpuacct_percpu_seq_show(struct seq_file *m,
 
 static int cpuacct_percpu_user_seq_show(struct seq_file *m, void *V)
 {
-	return __cpuacct_percpu_seq_show(m, CPUACCT_USAGE_USER);
+	return __cpuacct_percpu_seq_show(m, CPUACCT_STAT_USER);
 }
 
 static int cpuacct_percpu_sys_seq_show(struct seq_file *m, void *V)
 {
-	return __cpuacct_percpu_seq_show(m, CPUACCT_USAGE_SYSTEM);
+	return __cpuacct_percpu_seq_show(m, CPUACCT_STAT_SYSTEM);
 }
 
 static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
 {
-	return __cpuacct_percpu_seq_show(m, CPUACCT_USAGE_NRUSAGE);
+	return __cpuacct_percpu_seq_show(m, CPUACCT_STAT_NSTATS);
 }
 
-static const char * const cpuacct_stat_desc[] = {
-	[CPUACCT_STAT_USER] = "user",
-	[CPUACCT_STAT_SYSTEM] = "system",
-};
-
 static int cpuacct_stats_show(struct seq_file *sf, void *v)
 {
 	struct cpuacct *ca = css_ca(seq_css(sf));
@@ -316,11 +309,11 @@ static struct cftype files[] = {
 void cpuacct_charge(struct task_struct *tsk, u64 cputime)
 {
 	struct cpuacct *ca;
-	int index = CPUACCT_USAGE_SYSTEM;
+	int index = CPUACCT_STAT_SYSTEM;
 	struct pt_regs *regs = task_pt_regs(tsk);
 
 	if (regs && user_mode(regs))
-		index = CPUACCT_USAGE_USER;
+		index = CPUACCT_STAT_USER;
 
 	rcu_read_lock();
 
-- 
1.8.5.1

[PATCH v2 2/3] cpuacct: Use loop to avoid copies of the similar code in cpuacct_stats_show()

[Zhao Lei]

Currently we have copies of the similar code for each cpustat(system/user)
in cpuacct_stats_show(), this patch use loop instead.
Only a little cleanup.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
---
 kernel/sched/cpuacct.c | 29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)

diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 74241eb..677cd1a 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -243,27 +243,26 @@ static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
 static int cpuacct_stats_show(struct seq_file *sf, void *v)
 {
 	struct cpuacct *ca = css_ca(seq_css(sf));
+	s64 val[CPUACCT_STAT_NSTATS];
 	int cpu;
-	s64 val = 0;
+	int stat;
 
+	memset(val, 0, sizeof(val));
 	for_each_possible_cpu(cpu) {
-		struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
-		val += kcpustat->cpustat[CPUTIME_USER];
-		val += kcpustat->cpustat[CPUTIME_NICE];
-	}
-	val = cputime64_to_clock_t(val);
-	seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_USER], val);
+		u64 *cpustat = per_cpu_ptr(ca->cpustat, cpu)->cpustat;
 
-	val = 0;
-	for_each_possible_cpu(cpu) {
-		struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
-		val += kcpustat->cpustat[CPUTIME_SYSTEM];
-		val += kcpustat->cpustat[CPUTIME_IRQ];
-		val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
+		val[CPUACCT_STAT_USER]   += cpustat[CPUTIME_USER];
+		val[CPUACCT_STAT_USER]   += cpustat[CPUTIME_NICE];
+		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SYSTEM];
+		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_IRQ];
+		val[CPUACCT_STAT_SYSTEM] += cpustat[CPUTIME_SOFTIRQ];
 	}
 
-	val = cputime64_to_clock_t(val);
-	seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
+	for (stat = 0; stat < CPUACCT_STAT_NSTATS; stat++) {
+		seq_printf(sf, "%s %lld\n",
+			   cpuacct_stat_desc[stat],
+			   cputime64_to_clock_t(val[stat]));
+	}
 
 	return 0;
 }
-- 
1.8.5.1

[PATCH v2 3/3] cpuacct: Show all detail stats in one file

[Zhao Lei]

In current code, we can get cpuacct data from severial files,
but each file have its lilmit.

For example:
we can get cpu usage in user and kernel mode by cpuacct.stat,
but we can't get detail data of each cpu in above file.
we can get each cpu's kernel mode usage in cpuacct.usage_percpu_sys,
but we can't get user mode data in the same time.

This patch introduce cpuacct.usage_all, to show all detailed
cpu accounting data altogether:
 # cat cpuacct.usage_all
 cpu user system
 0 3809760299 5807968992
 1 3250329855 454612211
 ..

Any aspects of statistics data can be get from this file
with a simple data-processing code.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
---
 kernel/sched/cpuacct.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 677cd1a..bc0b309c 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -240,6 +240,42 @@ static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
 	return __cpuacct_percpu_seq_show(m, CPUACCT_STAT_NSTATS);
 }
 
+static int cpuacct_all_seq_show(struct seq_file *m, void *V)
+{
+	struct cpuacct *ca = css_ca(seq_css(m));
+	int index;
+	int cpu;
+
+	seq_puts(m, "cpu");
+	for (index = 0; index < CPUACCT_STAT_NSTATS; index++)
+		seq_printf(m, " %s", cpuacct_stat_desc[index]);
+	seq_puts(m, "\n");
+
+	for_each_possible_cpu(cpu) {
+		struct cpuacct_usage *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
+
+		seq_printf(m, "%d", cpu);
+
+		for (index = 0; index < CPUACCT_STAT_NSTATS; index++) {
+#ifndef CONFIG_64BIT
+			/*
+			 * Take rq->lock to make 64-bit read safe on 32-bit
+			 * platforms.
+			 */
+			raw_spin_lock_irq(&cpu_rq(cpu)->lock);
+#endif
+
+			seq_printf(m, " %llu", cpuusage->usages[index]);
+
+#ifndef CONFIG_64BIT
+			raw_spin_unlock_irq(&cpu_rq(cpu)->lock);
+#endif
+		}
+		seq_puts(m, "\n");
+	}
+	return 0;
+}
+
 static int cpuacct_stats_show(struct seq_file *sf, void *v)
 {
 	struct cpuacct *ca = css_ca(seq_css(sf));
@@ -294,6 +330,10 @@ static struct cftype files[] = {
 		.seq_show = cpuacct_percpu_sys_seq_show,
 	},
 	{
+		.name = "usage_all",
+		.seq_show = cpuacct_all_seq_show,
+	},
+	{
 		.name = "stat",
 		.seq_show = cpuacct_stats_show,
 	},
-- 
1.8.5.1

Re: [PATCH v2 0/3] cpuacct: Show all detail stats in one file

[Ingo Molnar]

* Zhao Lei <zhaolei@cn.fujitsu.com> wrote:

>  1: Rewrite subject and changelog to fix typos and
>     make it more accurate.

So this is really annoying. In the previous review I suggested this:

 " - please fix the title of the patch: have a look at 'git log
     kernel/sched/cpuacct.c' how recent titles to that code look like. "

If you do what I suggested, you see this title:

    sched/cpuacct: Check for NULL when using task_pt_regs()

Yet you continued to submit using the tag I complained about:

    cpuacct: Show all detail stats in one file

Yes, it's a small detail that I could fix up, but this kind of inability to read 
very plain suggestions worries me.

And yes, if I look further, I see further signs of lack of care:

  In current code, we can get cpuacct data from severial files,

severial? How about at least running a spell checker over the text?

... and I haven't even looked at the code.

Thanks,

	Ingo