revert "Task Control Groups: example CPU accounting subsystem"

Revert 62d0df6.

This was originally intended as a simple initial example of how to create a
control groups subsystem; it wasn't intended for mainline, but I didn't make
this clear enough to Andrew.

The CFS cgroup subsystem now has better functionality for the per-cgroup usage
accounting (based directly on CFS stats) than the "usage" status file in this
patch, and the "load" status file is rather simplistic - although having a
per-cgroup load average report would be a useful feature, I don't believe this
patch actually provides it.  If it gets into the final 2.6.24 we'd probably
have to support this interface for ever.

Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/cgroup_subsys.h

@@ -13,12 +13,6 @@ SUBSYS(cpuset)
 
 /* */
 
-#ifdef CONFIG_CGROUP_CPUACCT
-SUBSYS(cpuacct)
-#endif
-
-/* */
-
 #ifdef CONFIG_CGROUP_DEBUG
 SUBSYS(debug)
 #endif

init/Kconfig

@@ -301,13 +301,6 @@ config CGROUP_NS
           for instance virtual servers and checkpoint/restart
           jobs.
 
-config CGROUP_CPUACCT
-	bool "Simple CPU accounting cgroup subsystem"
-	depends on CGROUPS
-	help
-	  Provides a simple Resource Controller for monitoring the
-	  total CPU consumed by the tasks in a cgroup
-
 config CPUSETS
 	bool "Cpuset support"
 	depends on SMP && CGROUPS

kernel/Makefile

@@ -40,7 +40,6 @@ obj-$(CONFIG_COMPAT) += compat.o
 obj-$(CONFIG_CGROUPS) += cgroup.o
 obj-$(CONFIG_CGROUP_DEBUG) += cgroup_debug.o
 obj-$(CONFIG_CPUSETS) += cpuset.o
-obj-$(CONFIG_CGROUP_CPUACCT) += cpu_acct.o
 obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o
 obj-$(CONFIG_IKCONFIG) += configs.o
 obj-$(CONFIG_STOP_MACHINE) += stop_machine.o

kernel/sched.c

@@ -52,7 +52,6 @@
 #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>
@@ -3338,13 +3337,9 @@ 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)
@@ -3408,10 +3403,9 @@ 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);
-		cpuacct_charge(p, cputime);
-	} else if (atomic_read(&rq->nr_iowait) > 0)
+	else if (atomic_read(&rq->nr_iowait) > 0)
 		cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
 	else
 		cpustat->idle = cputime64_add(cpustat->idle, tmp);
@@ -3447,10 +3441,8 @@ 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);
-	}
 }
 
 /*