Messages in this thread Patch in this message | | | From | Glauber Costa <> | Subject | [RFD 6/9] Report steal time for cgroup | Date | Fri, 23 Sep 2011 19:20:29 -0300 |
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This patch introduces a functionality commonly found in hypervisors: steal time.
For those not particularly familiar with it, steal time is defined as any time in which a virtual machine (or container) wanted to perform cpu work, but could not due to another VM/container being scheduled in its place. Note that idle time is never defined as steal time.
Assuming each container will live in its cgroup, we can very easily and nicely calculate steal time as all user/system time recorded in our sibling cgroups.
Signed-off-by: Glauber Costa <glommer@parallels.com> --- kernel/sched.c | 28 ++++++++++++++++++++++++++++ 1 files changed, 28 insertions(+), 0 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c index 7612410..8a510ab 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -9148,6 +9148,7 @@ int cpu_cgroup_proc_stat(struct cgroup *cgrp, struct cftype *cft, struct seq_fil unsigned int per_softirq_sums[NR_SOFTIRQS] = {0}; struct timespec boottime; struct task_group *tg; + struct task_group *sib; if (cgrp) tg = cgroup_tg(cgrp); @@ -9177,6 +9178,19 @@ int cpu_cgroup_proc_stat(struct cgroup *cgrp, struct cftype *cft, struct seq_fil irq = cputime64_add(irq, kstat->cpustat[IRQ]); softirq = cputime64_add(softirq, kstat->cpustat[SOFTIRQ]); steal = cputime64_add(steal, kstat->cpustat[STEAL]); + rcu_read_lock(); + list_for_each_entry(sib, &tg->siblings, siblings) { + struct kernel_stat *ksib; + if (!sib) + continue; + + ksib = per_cpu_ptr(sib->cpustat, i); + steal = cputime64_add(steal, ksib->cpustat[USER]); + steal = cputime64_add(steal, ksib->cpustat[SYSTEM]); + steal = cputime64_add(steal, ksib->cpustat[IRQ]); + steal = cputime64_add(steal, ksib->cpustat[SOFTIRQ]); + } + rcu_read_unlock(); guest = cputime64_add(guest, kstat->cpustat[GUEST]); guest_nice = cputime64_add(guest_nice, kstat->cpustat[GUEST_NICE]); @@ -9221,6 +9235,20 @@ int cpu_cgroup_proc_stat(struct cgroup *cgrp, struct cftype *cft, struct seq_fil irq = kstat->cpustat[IRQ]; softirq = kstat->cpustat[SOFTIRQ]; steal = kstat->cpustat[STEAL]; + rcu_read_lock(); + list_for_each_entry(sib, &tg->siblings, siblings) { + struct kernel_stat *ksib; + if (!sib) + continue; + + ksib = per_cpu_ptr(sib->cpustat, i); + steal = cputime64_add(steal, ksib->cpustat[USER]); + steal = cputime64_add(steal, ksib->cpustat[SYSTEM]); + steal = cputime64_add(steal, ksib->cpustat[IRQ]); + steal = cputime64_add(steal, ksib->cpustat[SOFTIRQ]); + } + rcu_read_unlock(); + guest = kstat->cpustat[GUEST]; guest_nice = kstat->cpustat[GUEST_NICE]; seq_printf(p, -- 1.7.6
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