Re: [PATCH v2 03/14] Move /proc/stat logic inside sched.c

From: Paul Turner
Date: Fri Nov 11 2011 - 20:35:21 EST

On 11/01/2011 02:19 PM, Glauber Costa wrote:
This patch moves all of the /proc/stat display code inside
sched.c. The goal is to later on, have a different version
of it per-cgroup. In containers environment, this is useful
to give each container a different and independent view of
the statistics displayed in this file.

Signed-off-by: Glauber Costa<glommer@xxxxxxxxxxxxx>
---
fs/proc/stat.c | 139 +-----------------------------------------------
include/linux/sched.h | 1 +
kernel/sched.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 144 insertions(+), 138 deletions(-)


This feels a little contrived. sched.c isn't the right place for much of this code. Why do you want to move it all instead of exporting the functionality (e.g. remove static?).

diff --git a/kernel/sched.c b/kernel/sched.c
index e78e1aa..3f42916 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -71,6 +71,7 @@
#include<linux/ctype.h>
#include<linux/ftrace.h>
#include<linux/slab.h>
+#include<linux/tick.h>

#include<asm/tlb.h>
#include<asm/irq_regs.h>
@@ -9494,6 +9495,147 @@ struct cgroup_subsys cpu_cgroup_subsys = {

#endif /* CONFIG_CGROUP_SCHED */

+#ifndef fi
+#define arch_irq_stat_cpu(cpu) 0
+#endif
+#ifndef arch_irq_stat
+#define arch_irq_stat() 0
+#endif
+#ifndef arch_idle_time
+#define arch_idle_time(cpu) 0
+#endif
+
+static u64 get_idle_time(int cpu)
+{
+ u64 idle, idle_time = get_cpu_idle_time_us(cpu, NULL);
+
+ if (idle_time == -1ULL) {
+ /* !NO_HZ so we can rely on cpustat.idle */
+ idle = kstat_cpu(cpu).cpustat[IDLE];
+ idle += arch_idle_time(cpu);
+ } else
+ idle = usecs_to_cputime(idle_time);
+
+ return idle;
+}
+
+static u64 get_iowait_time(int cpu)
+{
+ u64 iowait, iowait_time = get_cpu_iowait_time_us(cpu, NULL);
+
+ if (iowait_time == -1ULL)
+ /* !NO_HZ so we can rely on cpustat.iowait */
+ iowait = kstat_cpu(cpu).cpustat[IOWAIT];
+ else
+ iowait = usecs_to_cputime(iowait_time);
+
+ return iowait;
+}
+
+int cpu_cgroup_proc_stat(struct seq_file *p)
+{
+ int i, j;
+ unsigned long jif;
+ u64 user, nice, system, idle, iowait, irq, softirq, steal;
+ u64 guest, guest_nice;
+ u64 sum = 0;
+ u64 sum_softirq = 0;
+ unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
+ struct timespec boottime;
+
+ user = nice = system = idle = iowait =
+ irq = softirq = steal = 0;
+ guest = guest_nice = 0;
+ getboottime(&boottime);
+ jif = boottime.tv_sec;
+
+ for_each_possible_cpu(i) {
+ user += kstat_cpu(i).cpustat[USER];
+ nice += kstat_cpu(i).cpustat[NICE];
+ system += kstat_cpu(i).cpustat[SYSTEM];
+ idle += get_idle_time(i);
+ iowait += get_iowait_time(i);
+ irq += kstat_cpu(i).cpustat[IRQ];
+ softirq += kstat_cpu(i).cpustat[SOFTIRQ];
+ steal += kstat_cpu(i).cpustat[STEAL];
+ guest += kstat_cpu(i).cpustat[GUEST];
+ guest_nice += kstat_cpu(i).cpustat[GUEST_NICE];
+
+ for (j = 0; j< NR_SOFTIRQS; j++) {
+ unsigned int softirq_stat = kstat_softirqs_cpu(j, i);
+
+ per_softirq_sums[j] += softirq_stat;
+ sum_softirq += softirq_stat;
+ }
+ }
+ sum += arch_irq_stat();
+
+ seq_printf(p, "cpu %llu %llu %llu %llu %llu %llu %llu %llu %llu "
+ "%llu\n",
+ (unsigned long long)cputime64_to_clock_t(user),
+ (unsigned long long)cputime64_to_clock_t(nice),
+ (unsigned long long)cputime64_to_clock_t(system),
+ (unsigned long long)cputime64_to_clock_t(idle),
+ (unsigned long long)cputime64_to_clock_t(iowait),
+ (unsigned long long)cputime64_to_clock_t(irq),
+ (unsigned long long)cputime64_to_clock_t(softirq),
+ (unsigned long long)cputime64_to_clock_t(steal),
+ (unsigned long long)cputime64_to_clock_t(guest),
+ (unsigned long long)cputime64_to_clock_t(guest_nice));
+ for_each_online_cpu(i) {
+ /* Copy values here to work around gcc-2.95.3, gcc-2.96 */

GCC 3.2 is the listed current minimum requirement. If this code is being revisited this could be cleaned up.

+ user = kstat_cpu(i).cpustat[USER];
+ nice = kstat_cpu(i).cpustat[NICE];
+ system = kstat_cpu(i).cpustat[SYSTEM];
+ idle = get_idle_time(i);
+ iowait = get_iowait_time(i);
+ irq = kstat_cpu(i).cpustat[IRQ];
+ softirq = kstat_cpu(i).cpustat[SOFTIRQ];
+ steal = kstat_cpu(i).cpustat[STEAL];
+ guest = kstat_cpu(i).cpustat[GUEST];
+ guest_nice = kstat_cpu(i).cpustat[GUEST_NICE];
+ seq_printf(p,
+ "cpu%d %llu %llu %llu %llu %llu %llu %llu %llu %llu "
+ "%llu\n",
+ i,
+ (unsigned long long)cputime64_to_clock_t(user),
+ (unsigned long long)cputime64_to_clock_t(nice),
+ (unsigned long long)cputime64_to_clock_t(system),
+ (unsigned long long)cputime64_to_clock_t(idle),
+ (unsigned long long)cputime64_to_clock_t(iowait),
+ (unsigned long long)cputime64_to_clock_t(irq),
+ (unsigned long long)cputime64_to_clock_t(softirq),
+ (unsigned long long)cputime64_to_clock_t(steal),
+ (unsigned long long)cputime64_to_clock_t(guest),
+ (unsigned long long)cputime64_to_clock_t(guest_nice));
+ }
+ seq_printf(p, "intr %llu", (unsigned long long)sum);
+
+ /* sum again ? it could be updated? */
+ for_each_irq_nr(j)
+ seq_printf(p, " %u", kstat_irqs(j));
+
+ seq_printf(p,
+ "\nctxt %llu\n"
+ "btime %lu\n"
+ "processes %lu\n"
+ "procs_running %lu\n"
+ "procs_blocked %lu\n",
+ nr_context_switches(),
+ (unsigned long)jif,
+ total_forks,
+ nr_running(),
+ nr_iowait());
+
+ seq_printf(p, "softirq %llu", (unsigned long long)sum_softirq);
+
+ for (i = 0; i< NR_SOFTIRQS; i++)
+ seq_printf(p, " %u", per_softirq_sums[i]);
+ seq_putc(p, '\n');
+
+ return 0;
+}
+
#ifdef CONFIG_CGROUP_CPUACCT

/*

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