Task Control Groups: example CPU accounting subsystem

This example demonstrates how to use the generic cgroup subsystem for a
simple resource tracker that counts, for the processes in a cgroup, the
total CPU time used and the %CPU used in the last complete 10 second interval.

Portions contributed by Balbir Singh <balbir@in.ibm.com>

Signed-off-by: Paul Menage <menage@google.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 3 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index ed90be46fb31..72a2a16e2214 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -51,6 +51,7 @@
 #include <linux/cpu.h>
 #include <linux/cpuset.h>
 #include <linux/percpu.h>
+#include <linux/cpu_acct.h>
 #include <linux/kthread.h>
 #include <linux/seq_file.h>
 #include <linux/sysctl.h>
@@ -3307,9 +3308,13 @@ void account_user_time(struct task_struct *p, cputime_t cputime)
 {
         struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
         cputime64_t tmp;
+        struct rq *rq = this_rq();
 
         p->utime = cputime_add(p->utime, cputime);
 
+        if (p != rq->idle)
+                cpuacct_charge(p, cputime);
+
         /* Add user time to cpustat. */
         tmp = cputime_to_cputime64(cputime);
         if (TASK_NICE(p) > 0)
@@ -3374,9 +3379,10 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
                 cpustat->irq = cputime64_add(cpustat->irq, tmp);
         else if (softirq_count())
                 cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
-        else if (p != rq->idle)
+        else if (p != rq->idle) {
                 cpustat->system = cputime64_add(cpustat->system, tmp);
-        else if (atomic_read(&rq->nr_iowait) > 0)
+                cpuacct_charge(p, cputime);
+        } else if (atomic_read(&rq->nr_iowait) > 0)
                 cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
         else
                 cpustat->idle = cputime64_add(cpustat->idle, tmp);
@@ -3412,8 +3418,10 @@ void account_steal_time(struct task_struct *p, cputime_t steal)
                         cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
                 else
                         cpustat->idle = cputime64_add(cpustat->idle, tmp);
-        } else
+        } else {
                 cpustat->steal = cputime64_add(cpustat->steal, tmp);
+                cpuacct_charge(p, -tmp);
+        }
 }
 
 /*