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Commit ce0e7b28 authored by Ryota Ozaki's avatar Ryota Ozaki Committed by Ingo Molnar
Browse files

sched, cpuacct: Fix niced guest time accounting 

CPU time of a guest is always accounted in 'user' time
without concern for the nice value of its counterpart
process although the guest is scheduled under the nice
value.

This patch fixes the defect and accounts cpu time of
a niced guest in 'nice' time as same as a niced process.

And also the patch adds 'guest_nice' to cpuacct. The
value provides niced guest cpu time which is like 'nice'
to 'user'.

The original discussions can be found here:

  http://www.mail-archive.com/kvm@vger.kernel.org/msg23982.html
  http://www.mail-archive.com/kvm@vger.kernel.org/msg23860.html



Signed-off-by: default avatarRyota Ozaki <ozaki.ryota@gmail.com>
Acked-by: default avatarAvi Kivity <avi@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1256314810-7897-1-git-send-email-ozaki.ryota@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 0b9e31e9

Documentation/filesystems/proc.txt

+2 −1
Original line number Diff line number Diff line
@@ -1072,7 +1072,8 @@ second). The meanings of the columns are as follows, from left to right: 
- irq: servicing interrupts

- softirq: servicing softirqs

- steal: involuntary wait

- guest: running a guest

- guest: running a normal guest

- guest_nice: running a niced guest



The "intr" line gives counts of interrupts  serviced since boot time, for each

of the  possible system interrupts.   The first  column  is the  total of  all

fs/proc/stat.c

+13 −6
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ static int show_stat(struct seq_file *p, void *v) 
	int i, j;

	unsigned long jif;

	cputime64_t user, nice, system, idle, iowait, irq, softirq, steal;

	cputime64_t guest;

	cputime64_t guest, guest_nice;

	u64 sum = 0;

	u64 sum_softirq = 0;

	unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
@@ -36,7 +36,7 @@ static int show_stat(struct seq_file *p, void *v) 


	user = nice = system = idle = iowait =

		irq = softirq = steal = cputime64_zero;

	guest = cputime64_zero;

	guest = guest_nice = cputime64_zero;

	getboottime(&boottime);

	jif = boottime.tv_sec;
@@ -51,6 +51,8 @@ static int show_stat(struct seq_file *p, void *v) 
		softirq = cputime64_add(softirq, kstat_cpu(i).cpustat.softirq);

		steal = cputime64_add(steal, kstat_cpu(i).cpustat.steal);

		guest = cputime64_add(guest, kstat_cpu(i).cpustat.guest);

		guest_nice = cputime64_add(guest_nice,

			kstat_cpu(i).cpustat.guest_nice);

		for_each_irq_nr(j) {

			sum += kstat_irqs_cpu(j, i);

		}
@@ -65,7 +67,8 @@ static int show_stat(struct seq_file *p, void *v) 
	}

	sum += arch_irq_stat();



	seq_printf(p, "cpu  %llu %llu %llu %llu %llu %llu %llu %llu %llu\n",

	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),
@@ -74,7 +77,8 @@ static int show_stat(struct seq_file *p, void *v) 
		(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),

		(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 */
@@ -88,8 +92,10 @@ static int show_stat(struct seq_file *p, void *v) 
		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\n",

			"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),
@@ -99,7 +105,8 @@ static int show_stat(struct seq_file *p, void *v) 
			(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),

			(unsigned long long)cputime64_to_clock_t(guest_nice));

	}

	seq_printf(p, "intr %llu", (unsigned long long)sum);

include/linux/kernel_stat.h

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ struct cpu_usage_stat { 
	cputime64_t iowait;

	cputime64_t steal;

	cputime64_t guest;

	cputime64_t guest_nice;

};



struct kernel_stat {

kernel/sched.c

+7 −2
Original line number Diff line number Diff line
@@ -5017,9 +5017,14 @@ static void account_guest_time(struct task_struct *p, cputime_t cputime, 
	p->gtime = cputime_add(p->gtime, cputime);



	/* Add guest time to cpustat. */

	if (TASK_NICE(p) > 0) {

		cpustat->nice = cputime64_add(cpustat->nice, tmp);

		cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp);

	} else {

		cpustat->user = cputime64_add(cpustat->user, tmp);

		cpustat->guest = cputime64_add(cpustat->guest, tmp);

	}

}



/*

 * Account system cpu time to a process.