* [PATCH 0/3] Report guest steal time in host
@ 2015-05-06 10:58 Naveen N. Rao
2015-05-06 10:58 ` [PATCH 1/3] procfs: add guest steal time in /proc/<pid>/stat Naveen N. Rao
` (3 more replies)
0 siblings, 4 replies; 6+ messages in thread
From: Naveen N. Rao @ 2015-05-06 10:58 UTC (permalink / raw)
To: linux-kernel, linux-arch, kvm, linuxppc-dev, linux-s390
Cc: paulus, mpe, agraf, mingo, ego
Steal time accounts the time duration during which a guest vcpu was ready to
run, but was not scheduled to run by the hypervisor. This is particularly
relevant in cloud environment where customers would want to use this as an
indicator that their guests are being throttled. However, as it stands today,
guest steal time information is not visible from the hypervisor.
For cloud service providers, this is problematic since they would want to
overcommit cpu resources to achieve optimum resource utilization while at the
same time ensuring guests are not throttled. It is useful for service providers
to have access to the guest steal time data so that they can base their
overcommit/guest packing decisions on this. Higher guest steal time can be used
as a trigger to change how the guests are scheduled, or even migrate guests out
of a system.
This patchset attempts to make the guest steal times available in the host.
This is achieved by introducing a new field in per-task statistics
(/proc/<pid>/stat and /proc/<pid>/task/<pid>/stat) to accumulate per-vcpu steal
time. Programs (such as pidstat) can then be enhanced to report this
information on a per-thread basis.
This should also work for nested virtualization: steal time information for the
guest is readable via /proc/stat, while steal time information for guests
hosted on this hypervisor is readable via /proc/<pid>/task/*/stat.
Also, mpstat always shows steal time information for current (self) guest on a
per-cpu basis. And pidstat can be enhanced to report the same for the hosted
guests on a per-vcpu basis.
As an example:
Guest (self) steal time information using mpstat:
------------------------------------------------
mpstat is run from within the guest.
[root@rhel7-img ~]# mpstat -P ALL 1
Linux 3.19.0nnr (rhel7-img) 04/15/2015 _ppc64_ (4 CPU)
03:13:23 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle
03:13:24 PM all 12.25 0.00 1.25 0.00 1.00 2.25 13.75 0.00 0.00 69.50
03:13:24 PM 0 46.53 0.00 0.00 0.00 0.00 4.95 45.54 0.00 0.00 2.97
03:13:24 PM 1 0.00 0.00 0.00 0.00 0.00 4.04 3.03 0.00 0.00 92.93
03:13:24 PM 2 0.00 0.00 0.00 0.00 3.96 0.99 2.97 0.00 0.00 92.08
03:13:24 PM 3 3.00 0.00 4.00 0.00 0.00 0.00 4.00 0.00 0.00 89.00
03:13:24 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle
03:13:25 PM all 12.59 0.00 0.00 0.00 0.00 0.25 12.35 0.00 0.00 74.81
03:13:25 PM 0 50.00 0.00 0.00 0.00 0.00 0.98 49.02 0.00 0.00 0.00
03:13:25 PM 1 0.98 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 99.02
03:13:25 PM 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00
03:13:25 PM 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00
03:13:25 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle
03:13:26 PM all 12.99 0.00 0.00 0.00 0.25 0.00 12.75 0.00 0.00 74.02
03:13:26 PM 0 51.96 0.00 0.00 0.00 0.00 0.00 48.04 0.00 0.00 0.00
03:13:26 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00
03:13:26 PM 2 0.00 0.00 0.00 0.00 0.98 0.00 2.94 0.00 0.00 96.08
03:13:26 PM 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00
03:13:26 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle
03:13:27 PM all 12.53 0.00 1.00 0.25 0.00 0.25 12.03 0.00 0.00 73.93
03:13:27 PM 0 51.02 0.00 0.00 0.00 0.00 0.00 48.98 0.00 0.00 0.00
03:13:27 PM 1 0.00 0.00 4.04 0.00 0.00 0.00 0.00 0.00 0.00 95.96
03:13:27 PM 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00
03:13:27 PM 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00
Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle
Average: all 12.91 0.00 0.54 0.01 0.04 0.12 12.39 0.00 0.00 74.00
Average: 0 51.36 0.00 0.03 0.00 0.03 0.26 48.27 0.00 0.00 0.05
Average: 1 0.02 0.00 1.54 0.02 0.02 0.15 0.36 0.00 0.00 97.89
Average: 2 0.00 0.00 0.52 0.00 0.09 0.02 0.36 0.00 0.00 99.02
Average: 3 0.05 0.00 0.07 0.00 0.02 0.09 0.34 0.00 0.00 99.43
Steal time information for hosted guests in host using (locally modified) pidstat:
---------------------------------------------------------------------------------
pidstat is being run in the host.
[naveen@xxxxxxxxxx sysstat]$ ./pidstat -C qemu -tIu 1
Linux 3.19.0nnr (xxxxxxxxxx.in.ibm.com) 04/15/2015 _ppc64_ (64 CPU)
04:43:20 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command
04:43:22 AM 1008 3001 - 0.00 0.00 54.21 3.39 45.79 12 qemu-system-ppc
04:43:22 AM 1008 - 3005 0.00 0.00 54.21 3.39 0.00 12 |__qemu-system-ppc
04:43:22 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command
04:43:23 AM 1008 3001 - 0.00 0.00 52.00 3.25 46.00 12 qemu-system-ppc
04:43:23 AM 1008 - 3003 0.00 0.00 2.00 0.12 46.00 12 |__qemu-system-ppc
04:43:23 AM 1008 - 3005 0.00 0.00 45.00 2.81 0.00 12 |__qemu-system-ppc
04:43:23 AM 1008 - 3006 0.00 0.00 6.00 0.38 0.00 12 |__qemu-system-ppc
04:43:23 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command
04:43:24 AM 1008 3001 - 0.00 2.00 50.00 3.25 67.00 12 qemu-system-ppc
04:43:24 AM 1008 - 3001 0.00 1.00 0.00 0.06 0.00 12 |__qemu-system-ppc
04:43:24 AM 1008 - 3003 0.00 0.00 8.00 0.50 49.00 12 |__qemu-system-ppc
04:43:24 AM 1008 - 3004 0.00 0.00 2.00 0.12 5.00 12 |__qemu-system-ppc
04:43:24 AM 1008 - 3005 0.00 0.00 38.00 2.38 3.00 12 |__qemu-system-ppc
04:43:24 AM 1008 - 3006 0.00 1.00 0.00 0.06 8.00 12 |__qemu-system-ppc
04:43:24 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command
04:43:25 AM 1008 3001 - 0.00 0.00 51.00 3.19 47.00 12 qemu-system-ppc
04:43:25 AM 1008 - 3003 0.00 0.00 27.00 1.69 47.00 12 |__qemu-system-ppc
04:43:25 AM 1008 - 3004 0.00 1.00 0.00 0.06 0.00 12 |__qemu-system-ppc
04:43:25 AM 1008 - 3005 0.00 1.00 23.00 1.50 0.00 12 |__qemu-system-ppc
04:43:25 AM 1008 - 3006 0.00 0.00 2.00 0.12 0.00 12 |__qemu-system-ppc
04:43:25 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command
04:43:26 AM 1008 3001 - 0.00 0.00 51.00 3.18 53.00 12 qemu-system-ppc
04:43:26 AM 1008 - 3003 0.00 0.00 9.00 0.56 50.00 12 |__qemu-system-ppc
04:43:26 AM 1008 - 3005 0.00 0.00 16.00 1.00 3.00 12 |__qemu-system-ppc
04:43:26 AM 1008 - 3006 0.00 0.00 26.00 1.62 0.00 12 |__qemu-system-ppc
Average: UID TGID TID %usr %system %guest %CPU %steal CPU Command
Average: 1008 3001 - 0.00 0.18 51.54 3.23 50.12 - qemu-system-ppc
Average: 1008 - 3001 0.02 0.02 0.00 0.00 0.00 - |__qemu-system-ppc
Average: 1008 - 3003 0.00 0.03 15.89 0.99 48.24 - |__qemu-system-ppc
Average: 1008 - 3004 0.00 0.05 11.70 0.73 0.56 - |__qemu-system-ppc
Average: 1008 - 3005 0.00 0.06 20.03 1.26 0.58 - |__qemu-system-ppc
Average: 1008 - 3006 0.00 0.03 3.93 0.25 0.72 - |__qemu-system-ppc
Thanks!
- Naveen
------
Changes since RFC: Updated description to clarify few aspects that I got
questions about. No code changes.
Naveen N. Rao (3):
procfs: add guest steal time in /proc/<pid>/stat
kvm/x86: report guest steal time in host
kvm/powerpc: report guest steal time in host
arch/powerpc/include/asm/kvm_host.h | 1 +
arch/powerpc/kernel/asm-offsets.c | 1 +
arch/powerpc/kvm/book3s_hv.c | 2 ++
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 3 +++
arch/x86/kvm/x86.c | 1 +
fs/proc/array.c | 6 ++++++
include/linux/sched.h | 7 +++++++
kernel/fork.c | 2 +-
8 files changed, 22 insertions(+), 1 deletion(-)
--
2.3.5
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH 1/3] procfs: add guest steal time in /proc/<pid>/stat 2015-05-06 10:58 [PATCH 0/3] Report guest steal time in host Naveen N. Rao @ 2015-05-06 10:58 ` Naveen N. Rao 2015-05-06 10:58 ` [PATCH 2/3] kvm/x86: report guest steal time in host Naveen N. Rao ` (2 subsequent siblings) 3 siblings, 0 replies; 6+ messages in thread From: Naveen N. Rao @ 2015-05-06 10:58 UTC (permalink / raw) To: linux-kernel, linux-arch, kvm, linuxppc-dev, linux-s390 Cc: paulus, mpe, agraf, mingo, ego Introduce a field in /proc/<pid>/stat to expose guest steal time. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- fs/proc/array.c | 6 ++++++ include/linux/sched.h | 7 +++++++ kernel/fork.c | 2 +- 3 files changed, 14 insertions(+), 1 deletion(-) diff --git a/fs/proc/array.c b/fs/proc/array.c index 1295a00..d86f00e 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -363,6 +363,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, unsigned long rsslim = 0; char tcomm[sizeof(task->comm)]; unsigned long flags; + cputime_t gstime; state = *get_task_state(task); vsize = eip = esp = 0; @@ -382,6 +383,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, sigemptyset(&sigcatch); cutime = cstime = utime = stime = 0; cgtime = gtime = 0; + gstime = 0; if (lock_task_sighand(task, &flags)) { struct signal_struct *sig = task->signal; @@ -410,6 +412,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, min_flt += t->min_flt; maj_flt += t->maj_flt; gtime += task_gtime(t); + gstime += task_gstime(t); } while_each_thread(task, t); min_flt += sig->min_flt; @@ -432,6 +435,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, maj_flt = task->maj_flt; task_cputime_adjusted(task, &utime, &stime); gtime = task_gtime(task); + gstime = task_gstime(task); } /* scale priority and nice values from timeslices to -20..20 */ @@ -505,6 +509,8 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, else seq_put_decimal_ll(m, ' ', 0); + seq_put_decimal_ull(m, ' ', cputime_to_clock_t(gstime)); + seq_putc(m, '\n'); if (mm) mmput(mm); diff --git a/include/linux/sched.h b/include/linux/sched.h index 0eabab9..cb57954 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1429,6 +1429,7 @@ struct task_struct { cputime_t utime, stime, utimescaled, stimescaled; cputime_t gtime; + cputime_t gstime; #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE struct cputime prev_cputime; #endif @@ -1955,6 +1956,12 @@ static inline cputime_t task_gtime(struct task_struct *t) return t->gtime; } #endif + +static inline cputime_t task_gstime(struct task_struct *t) +{ + return t->gstime; +} + extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st); extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st); diff --git a/kernel/fork.c b/kernel/fork.c index cf65139..529ebe5 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1293,7 +1293,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, init_sigpending(&p->pending); - p->utime = p->stime = p->gtime = 0; + p->utime = p->stime = p->gtime = p->gstime = 0; p->utimescaled = p->stimescaled = 0; #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE p->prev_cputime.utime = p->prev_cputime.stime = 0; -- 2.3.5 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 2/3] kvm/x86: report guest steal time in host 2015-05-06 10:58 [PATCH 0/3] Report guest steal time in host Naveen N. Rao 2015-05-06 10:58 ` [PATCH 1/3] procfs: add guest steal time in /proc/<pid>/stat Naveen N. Rao @ 2015-05-06 10:58 ` Naveen N. Rao 2015-05-06 10:58 ` [PATCH 3/3] kvm/powerpc: " Naveen N. Rao 2015-05-06 11:55 ` [PATCH 0/3] Report " Naveen N. Rao 3 siblings, 0 replies; 6+ messages in thread From: Naveen N. Rao @ 2015-05-06 10:58 UTC (permalink / raw) To: linux-kernel, linux-arch, kvm, linuxppc-dev, linux-s390 Cc: paulus, mpe, agraf, mingo, ego Report guest steal time in host task statistics. On x86, this is just the scheduler run_delay. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- arch/x86/kvm/x86.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0ee725f..737b0e4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2094,6 +2094,7 @@ static void record_steal_time(struct kvm_vcpu *vcpu) vcpu->arch.st.steal.steal += vcpu->arch.st.accum_steal; vcpu->arch.st.steal.version += 2; + current->gstime += vcpu->arch.st.accum_steal; vcpu->arch.st.accum_steal = 0; kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime, -- 2.3.5 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 3/3] kvm/powerpc: report guest steal time in host 2015-05-06 10:58 [PATCH 0/3] Report guest steal time in host Naveen N. Rao 2015-05-06 10:58 ` [PATCH 1/3] procfs: add guest steal time in /proc/<pid>/stat Naveen N. Rao 2015-05-06 10:58 ` [PATCH 2/3] kvm/x86: report guest steal time in host Naveen N. Rao @ 2015-05-06 10:58 ` Naveen N. Rao 2015-05-06 11:55 ` [PATCH 0/3] Report " Naveen N. Rao 3 siblings, 0 replies; 6+ messages in thread From: Naveen N. Rao @ 2015-05-06 10:58 UTC (permalink / raw) To: linux-kernel, linux-arch, kvm, linuxppc-dev, linux-s390 Cc: paulus, mpe, agraf, mingo, ego On powerpc, kvm tracks both the guest steal time as well as the time when guest was idle and this gets sent in to the guest through DTL. The guest accounts these entries as either steal time or idle time based on the last running task. Since the true guest idle status is not visible to the host, we can't accurately expose the guest steal time in the host. However, tracking the guest vcpu cede status can get us a reasonable (within 5% variation) vcpu steal time since guest vcpus cede the processor on entering the idle task. To do this, we introduce a new field ceded_st in kvm_vcpu_arch structure to accurately track the guest vcpu cede status (this is needed since the existing ceded field is modified before we can use it). During DTL entry creation, we check this flag and account the time as stolen if the guest vcpu had not ceded. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- Tests show that the steal time being reported in the host with this approach is around 5% higher than the steal time shown in guest. I'd be interested to know if there are ways to achieve better accounting of the guest steal time in host. arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kvm/book3s_hv.c | 2 ++ arch/powerpc/kvm/book3s_hv_rmhandlers.S | 3 +++ 4 files changed, 7 insertions(+) diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 8ef0512..7db48c4 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -655,6 +655,7 @@ struct kvm_vcpu_arch { u64 busy_preempt; u32 emul_inst; + u8 ceded_st; #endif }; diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 4717859..765c7c4 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -521,6 +521,7 @@ int main(void) DEFINE(VCPU_DEC_EXPIRES, offsetof(struct kvm_vcpu, arch.dec_expires)); DEFINE(VCPU_PENDING_EXC, offsetof(struct kvm_vcpu, arch.pending_exceptions)); DEFINE(VCPU_CEDED, offsetof(struct kvm_vcpu, arch.ceded)); + DEFINE(VCPU_CEDED_ST, offsetof(struct kvm_vcpu, arch.ceded_st)); DEFINE(VCPU_PRODDED, offsetof(struct kvm_vcpu, arch.prodded)); DEFINE(VCPU_MMCR, offsetof(struct kvm_vcpu, arch.mmcr)); DEFINE(VCPU_PMC, offsetof(struct kvm_vcpu, arch.pmc)); diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index de74756..ad7c0e3 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -545,6 +545,8 @@ static void kvmppc_create_dtl_entry(struct kvm_vcpu *vcpu, spin_lock_irq(&vcpu->arch.tbacct_lock); stolen += vcpu->arch.busy_stolen; vcpu->arch.busy_stolen = 0; + if (!vcpu->arch.ceded_st && stolen) + (pid_task(vcpu->pid, PIDTYPE_PID))->gstime += stolen; spin_unlock_irq(&vcpu->arch.tbacct_lock); if (!dt || !vpa) return; diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 6cbf163..28f304e 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -873,6 +873,7 @@ deliver_guest_interrupt: fast_guest_return: li r0,0 stb r0,VCPU_CEDED(r4) /* cancel cede */ + stb r0,VCPU_CEDED_ST(r4) /* cancel cede */ mtspr SPRN_HSRR0,r10 mtspr SPRN_HSRR1,r11 @@ -1889,6 +1890,7 @@ _GLOBAL(kvmppc_h_cede) std r11,VCPU_MSR(r3) li r0,1 stb r0,VCPU_CEDED(r3) + stb r0,VCPU_CEDED_ST(r3) sync /* order setting ceded vs. testing prodded */ lbz r5,VCPU_PRODDED(r3) cmpwi r5,0 @@ -2052,6 +2054,7 @@ kvm_cede_prodded: stb r0,VCPU_PRODDED(r3) sync /* order testing prodded vs. clearing ceded */ stb r0,VCPU_CEDED(r3) + stb r0,VCPU_CEDED_ST(r3) li r3,H_SUCCESS blr -- 2.3.5 ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 0/3] Report guest steal time in host 2015-05-06 10:58 [PATCH 0/3] Report guest steal time in host Naveen N. Rao ` (2 preceding siblings ...) 2015-05-06 10:58 ` [PATCH 3/3] kvm/powerpc: " Naveen N. Rao @ 2015-05-06 11:55 ` Naveen N. Rao 3 siblings, 0 replies; 6+ messages in thread From: Naveen N. Rao @ 2015-05-06 11:55 UTC (permalink / raw) To: linux-kernel, linux-arch, kvm, linuxppc-dev, linux-s390 Cc: paulus, mpe, agraf, mingo, ego Arrgh! Sorry about the headers. Please ignore this set. Will repost in a separate thread. - Naveen On 2015/05/06 04:28PM, Naveen N Rao wrote: > Steal time accounts the time duration during which a guest vcpu was ready to > run, but was not scheduled to run by the hypervisor. This is particularly > relevant in cloud environment where customers would want to use this as an > indicator that their guests are being throttled. However, as it stands today, > guest steal time information is not visible from the hypervisor. > > For cloud service providers, this is problematic since they would want to > overcommit cpu resources to achieve optimum resource utilization while at the > same time ensuring guests are not throttled. It is useful for service providers > to have access to the guest steal time data so that they can base their > overcommit/guest packing decisions on this. Higher guest steal time can be used > as a trigger to change how the guests are scheduled, or even migrate guests out > of a system. > > This patchset attempts to make the guest steal times available in the host. > This is achieved by introducing a new field in per-task statistics > (/proc/<pid>/stat and /proc/<pid>/task/<pid>/stat) to accumulate per-vcpu steal > time. Programs (such as pidstat) can then be enhanced to report this > information on a per-thread basis. > > This should also work for nested virtualization: steal time information for the > guest is readable via /proc/stat, while steal time information for guests > hosted on this hypervisor is readable via /proc/<pid>/task/*/stat. > > Also, mpstat always shows steal time information for current (self) guest on a > per-cpu basis. And pidstat can be enhanced to report the same for the hosted > guests on a per-vcpu basis. > > As an example: > > Guest (self) steal time information using mpstat: > ------------------------------------------------ > > mpstat is run from within the guest. > > [root@rhel7-img ~]# mpstat -P ALL 1 > Linux 3.19.0nnr (rhel7-img) 04/15/2015 _ppc64_ (4 CPU) > > 03:13:23 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle > 03:13:24 PM all 12.25 0.00 1.25 0.00 1.00 2.25 13.75 0.00 0.00 69.50 > 03:13:24 PM 0 46.53 0.00 0.00 0.00 0.00 4.95 45.54 0.00 0.00 2.97 > 03:13:24 PM 1 0.00 0.00 0.00 0.00 0.00 4.04 3.03 0.00 0.00 92.93 > 03:13:24 PM 2 0.00 0.00 0.00 0.00 3.96 0.99 2.97 0.00 0.00 92.08 > 03:13:24 PM 3 3.00 0.00 4.00 0.00 0.00 0.00 4.00 0.00 0.00 89.00 > > 03:13:24 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle > 03:13:25 PM all 12.59 0.00 0.00 0.00 0.00 0.25 12.35 0.00 0.00 74.81 > 03:13:25 PM 0 50.00 0.00 0.00 0.00 0.00 0.98 49.02 0.00 0.00 0.00 > 03:13:25 PM 1 0.98 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 99.02 > 03:13:25 PM 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 > 03:13:25 PM 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 > > 03:13:25 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle > 03:13:26 PM all 12.99 0.00 0.00 0.00 0.25 0.00 12.75 0.00 0.00 74.02 > 03:13:26 PM 0 51.96 0.00 0.00 0.00 0.00 0.00 48.04 0.00 0.00 0.00 > 03:13:26 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 > 03:13:26 PM 2 0.00 0.00 0.00 0.00 0.98 0.00 2.94 0.00 0.00 96.08 > 03:13:26 PM 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 > > 03:13:26 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle > 03:13:27 PM all 12.53 0.00 1.00 0.25 0.00 0.25 12.03 0.00 0.00 73.93 > 03:13:27 PM 0 51.02 0.00 0.00 0.00 0.00 0.00 48.98 0.00 0.00 0.00 > 03:13:27 PM 1 0.00 0.00 4.04 0.00 0.00 0.00 0.00 0.00 0.00 95.96 > 03:13:27 PM 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 > 03:13:27 PM 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 > > Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle > Average: all 12.91 0.00 0.54 0.01 0.04 0.12 12.39 0.00 0.00 74.00 > Average: 0 51.36 0.00 0.03 0.00 0.03 0.26 48.27 0.00 0.00 0.05 > Average: 1 0.02 0.00 1.54 0.02 0.02 0.15 0.36 0.00 0.00 97.89 > Average: 2 0.00 0.00 0.52 0.00 0.09 0.02 0.36 0.00 0.00 99.02 > Average: 3 0.05 0.00 0.07 0.00 0.02 0.09 0.34 0.00 0.00 99.43 > > Steal time information for hosted guests in host using (locally modified) pidstat: > --------------------------------------------------------------------------------- > > pidstat is being run in the host. > > [naveen@xxxxxxxxxx sysstat]$ ./pidstat -C qemu -tIu 1 > Linux 3.19.0nnr (xxxxxxxxxx.in.ibm.com) 04/15/2015 _ppc64_ (64 CPU) > > 04:43:20 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command > 04:43:22 AM 1008 3001 - 0.00 0.00 54.21 3.39 45.79 12 qemu-system-ppc > 04:43:22 AM 1008 - 3005 0.00 0.00 54.21 3.39 0.00 12 |__qemu-system-ppc > > 04:43:22 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command > 04:43:23 AM 1008 3001 - 0.00 0.00 52.00 3.25 46.00 12 qemu-system-ppc > 04:43:23 AM 1008 - 3003 0.00 0.00 2.00 0.12 46.00 12 |__qemu-system-ppc > 04:43:23 AM 1008 - 3005 0.00 0.00 45.00 2.81 0.00 12 |__qemu-system-ppc > 04:43:23 AM 1008 - 3006 0.00 0.00 6.00 0.38 0.00 12 |__qemu-system-ppc > > 04:43:23 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command > 04:43:24 AM 1008 3001 - 0.00 2.00 50.00 3.25 67.00 12 qemu-system-ppc > 04:43:24 AM 1008 - 3001 0.00 1.00 0.00 0.06 0.00 12 |__qemu-system-ppc > 04:43:24 AM 1008 - 3003 0.00 0.00 8.00 0.50 49.00 12 |__qemu-system-ppc > 04:43:24 AM 1008 - 3004 0.00 0.00 2.00 0.12 5.00 12 |__qemu-system-ppc > 04:43:24 AM 1008 - 3005 0.00 0.00 38.00 2.38 3.00 12 |__qemu-system-ppc > 04:43:24 AM 1008 - 3006 0.00 1.00 0.00 0.06 8.00 12 |__qemu-system-ppc > > 04:43:24 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command > 04:43:25 AM 1008 3001 - 0.00 0.00 51.00 3.19 47.00 12 qemu-system-ppc > 04:43:25 AM 1008 - 3003 0.00 0.00 27.00 1.69 47.00 12 |__qemu-system-ppc > 04:43:25 AM 1008 - 3004 0.00 1.00 0.00 0.06 0.00 12 |__qemu-system-ppc > 04:43:25 AM 1008 - 3005 0.00 1.00 23.00 1.50 0.00 12 |__qemu-system-ppc > 04:43:25 AM 1008 - 3006 0.00 0.00 2.00 0.12 0.00 12 |__qemu-system-ppc > > 04:43:25 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command > 04:43:26 AM 1008 3001 - 0.00 0.00 51.00 3.18 53.00 12 qemu-system-ppc > 04:43:26 AM 1008 - 3003 0.00 0.00 9.00 0.56 50.00 12 |__qemu-system-ppc > 04:43:26 AM 1008 - 3005 0.00 0.00 16.00 1.00 3.00 12 |__qemu-system-ppc > 04:43:26 AM 1008 - 3006 0.00 0.00 26.00 1.62 0.00 12 |__qemu-system-ppc > > Average: UID TGID TID %usr %system %guest %CPU %steal CPU Command > Average: 1008 3001 - 0.00 0.18 51.54 3.23 50.12 - qemu-system-ppc > Average: 1008 - 3001 0.02 0.02 0.00 0.00 0.00 - |__qemu-system-ppc > Average: 1008 - 3003 0.00 0.03 15.89 0.99 48.24 - |__qemu-system-ppc > Average: 1008 - 3004 0.00 0.05 11.70 0.73 0.56 - |__qemu-system-ppc > Average: 1008 - 3005 0.00 0.06 20.03 1.26 0.58 - |__qemu-system-ppc > Average: 1008 - 3006 0.00 0.03 3.93 0.25 0.72 - |__qemu-system-ppc > > > Thanks! > - Naveen > > ------ > Changes since RFC: Updated description to clarify few aspects that I got > questions about. No code changes. > > > Naveen N. Rao (3): > procfs: add guest steal time in /proc/<pid>/stat > kvm/x86: report guest steal time in host > kvm/powerpc: report guest steal time in host > > arch/powerpc/include/asm/kvm_host.h | 1 + > arch/powerpc/kernel/asm-offsets.c | 1 + > arch/powerpc/kvm/book3s_hv.c | 2 ++ > arch/powerpc/kvm/book3s_hv_rmhandlers.S | 3 +++ > arch/x86/kvm/x86.c | 1 + > fs/proc/array.c | 6 ++++++ > include/linux/sched.h | 7 +++++++ > kernel/fork.c | 2 +- > 8 files changed, 22 insertions(+), 1 deletion(-) > > -- > 2.3.5 > ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 0/3] Report guest steal time in host @ 2015-05-06 11:56 Naveen N. Rao 0 siblings, 0 replies; 6+ messages in thread From: Naveen N. Rao @ 2015-05-06 11:56 UTC (permalink / raw) To: linux-kernel, linux-arch, kvm, linuxppc-dev, linux-s390 Cc: paulus, mpe, agraf, mingo, ego, warrier Steal time accounts the time duration during which a guest vcpu was ready to run, but was not scheduled to run by the hypervisor. This is particularly relevant in cloud environment where customers would want to use this as an indicator that their guests are being throttled. However, as it stands today, guest steal time information is not visible from the hypervisor. For cloud service providers, this is problematic since they would want to overcommit cpu resources to achieve optimum resource utilization while at the same time ensuring guests are not throttled. It is useful for service providers to have access to the guest steal time data so that they can base their overcommit/guest packing decisions on this. Higher guest steal time can be used as a trigger to change how the guests are scheduled, or even migrate guests out of a system. This patchset attempts to make the guest steal times available in the host. This is achieved by introducing a new field in per-task statistics (/proc/<pid>/stat and /proc/<pid>/task/<pid>/stat) to accumulate per-vcpu steal time. Programs (such as pidstat) can then be enhanced to report this information on a per-thread basis. This should also work for nested virtualization: steal time information for the guest is readable via /proc/stat, while steal time information for guests hosted on this hypervisor is readable via /proc/<pid>/task/*/stat. Also, mpstat always shows steal time information for current (self) guest on a per-cpu basis. And pidstat can be enhanced to report the same for the hosted guests on a per-vcpu basis. As an example: Guest (self) steal time information using mpstat: ------------------------------------------------ mpstat is run from within the guest. [root@rhel7-img ~]# mpstat -P ALL 1 Linux 3.19.0nnr (rhel7-img) 04/15/2015 _ppc64_ (4 CPU) 03:13:23 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 03:13:24 PM all 12.25 0.00 1.25 0.00 1.00 2.25 13.75 0.00 0.00 69.50 03:13:24 PM 0 46.53 0.00 0.00 0.00 0.00 4.95 45.54 0.00 0.00 2.97 03:13:24 PM 1 0.00 0.00 0.00 0.00 0.00 4.04 3.03 0.00 0.00 92.93 03:13:24 PM 2 0.00 0.00 0.00 0.00 3.96 0.99 2.97 0.00 0.00 92.08 03:13:24 PM 3 3.00 0.00 4.00 0.00 0.00 0.00 4.00 0.00 0.00 89.00 03:13:24 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 03:13:25 PM all 12.59 0.00 0.00 0.00 0.00 0.25 12.35 0.00 0.00 74.81 03:13:25 PM 0 50.00 0.00 0.00 0.00 0.00 0.98 49.02 0.00 0.00 0.00 03:13:25 PM 1 0.98 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 99.02 03:13:25 PM 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:13:25 PM 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:13:25 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 03:13:26 PM all 12.99 0.00 0.00 0.00 0.25 0.00 12.75 0.00 0.00 74.02 03:13:26 PM 0 51.96 0.00 0.00 0.00 0.00 0.00 48.04 0.00 0.00 0.00 03:13:26 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:13:26 PM 2 0.00 0.00 0.00 0.00 0.98 0.00 2.94 0.00 0.00 96.08 03:13:26 PM 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:13:26 PM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle 03:13:27 PM all 12.53 0.00 1.00 0.25 0.00 0.25 12.03 0.00 0.00 73.93 03:13:27 PM 0 51.02 0.00 0.00 0.00 0.00 0.00 48.98 0.00 0.00 0.00 03:13:27 PM 1 0.00 0.00 4.04 0.00 0.00 0.00 0.00 0.00 0.00 95.96 03:13:27 PM 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 03:13:27 PM 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 Average: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %gnice %idle Average: all 12.91 0.00 0.54 0.01 0.04 0.12 12.39 0.00 0.00 74.00 Average: 0 51.36 0.00 0.03 0.00 0.03 0.26 48.27 0.00 0.00 0.05 Average: 1 0.02 0.00 1.54 0.02 0.02 0.15 0.36 0.00 0.00 97.89 Average: 2 0.00 0.00 0.52 0.00 0.09 0.02 0.36 0.00 0.00 99.02 Average: 3 0.05 0.00 0.07 0.00 0.02 0.09 0.34 0.00 0.00 99.43 Steal time information for hosted guests in host using (locally modified) pidstat: --------------------------------------------------------------------------------- pidstat is being run in the host. [naveen@xxxxxxxxxx sysstat]$ ./pidstat -C qemu -tIu 1 Linux 3.19.0nnr (xxxxxxxxxx.in.ibm.com) 04/15/2015 _ppc64_ (64 CPU) 04:43:20 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command 04:43:22 AM 1008 3001 - 0.00 0.00 54.21 3.39 45.79 12 qemu-system-ppc 04:43:22 AM 1008 - 3005 0.00 0.00 54.21 3.39 0.00 12 |__qemu-system-ppc 04:43:22 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command 04:43:23 AM 1008 3001 - 0.00 0.00 52.00 3.25 46.00 12 qemu-system-ppc 04:43:23 AM 1008 - 3003 0.00 0.00 2.00 0.12 46.00 12 |__qemu-system-ppc 04:43:23 AM 1008 - 3005 0.00 0.00 45.00 2.81 0.00 12 |__qemu-system-ppc 04:43:23 AM 1008 - 3006 0.00 0.00 6.00 0.38 0.00 12 |__qemu-system-ppc 04:43:23 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command 04:43:24 AM 1008 3001 - 0.00 2.00 50.00 3.25 67.00 12 qemu-system-ppc 04:43:24 AM 1008 - 3001 0.00 1.00 0.00 0.06 0.00 12 |__qemu-system-ppc 04:43:24 AM 1008 - 3003 0.00 0.00 8.00 0.50 49.00 12 |__qemu-system-ppc 04:43:24 AM 1008 - 3004 0.00 0.00 2.00 0.12 5.00 12 |__qemu-system-ppc 04:43:24 AM 1008 - 3005 0.00 0.00 38.00 2.38 3.00 12 |__qemu-system-ppc 04:43:24 AM 1008 - 3006 0.00 1.00 0.00 0.06 8.00 12 |__qemu-system-ppc 04:43:24 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command 04:43:25 AM 1008 3001 - 0.00 0.00 51.00 3.19 47.00 12 qemu-system-ppc 04:43:25 AM 1008 - 3003 0.00 0.00 27.00 1.69 47.00 12 |__qemu-system-ppc 04:43:25 AM 1008 - 3004 0.00 1.00 0.00 0.06 0.00 12 |__qemu-system-ppc 04:43:25 AM 1008 - 3005 0.00 1.00 23.00 1.50 0.00 12 |__qemu-system-ppc 04:43:25 AM 1008 - 3006 0.00 0.00 2.00 0.12 0.00 12 |__qemu-system-ppc 04:43:25 AM UID TGID TID %usr %system %guest %CPU %steal CPU Command 04:43:26 AM 1008 3001 - 0.00 0.00 51.00 3.18 53.00 12 qemu-system-ppc 04:43:26 AM 1008 - 3003 0.00 0.00 9.00 0.56 50.00 12 |__qemu-system-ppc 04:43:26 AM 1008 - 3005 0.00 0.00 16.00 1.00 3.00 12 |__qemu-system-ppc 04:43:26 AM 1008 - 3006 0.00 0.00 26.00 1.62 0.00 12 |__qemu-system-ppc Average: UID TGID TID %usr %system %guest %CPU %steal CPU Command Average: 1008 3001 - 0.00 0.18 51.54 3.23 50.12 - qemu-system-ppc Average: 1008 - 3001 0.02 0.02 0.00 0.00 0.00 - |__qemu-system-ppc Average: 1008 - 3003 0.00 0.03 15.89 0.99 48.24 - |__qemu-system-ppc Average: 1008 - 3004 0.00 0.05 11.70 0.73 0.56 - |__qemu-system-ppc Average: 1008 - 3005 0.00 0.06 20.03 1.26 0.58 - |__qemu-system-ppc Average: 1008 - 3006 0.00 0.03 3.93 0.25 0.72 - |__qemu-system-ppc - Naveen ------ Changes since RFC: Updated description to clarify few aspects that I got questions about. No code changes. Naveen N. Rao (3): procfs: add guest steal time in /proc/<pid>/stat kvm/x86: report guest steal time in host kvm/powerpc: report guest steal time in host arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kvm/book3s_hv.c | 2 ++ arch/powerpc/kvm/book3s_hv_rmhandlers.S | 3 +++ arch/x86/kvm/x86.c | 1 + fs/proc/array.c | 6 ++++++ include/linux/sched.h | 7 +++++++ kernel/fork.c | 2 +- 8 files changed, 22 insertions(+), 1 deletion(-) -- 2.3.7 ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2015-05-06 11:57 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2015-05-06 10:58 [PATCH 0/3] Report guest steal time in host Naveen N. Rao 2015-05-06 10:58 ` [PATCH 1/3] procfs: add guest steal time in /proc/<pid>/stat Naveen N. Rao 2015-05-06 10:58 ` [PATCH 2/3] kvm/x86: report guest steal time in host Naveen N. Rao 2015-05-06 10:58 ` [PATCH 3/3] kvm/powerpc: " Naveen N. Rao 2015-05-06 11:55 ` [PATCH 0/3] Report " Naveen N. Rao 2015-05-06 11:56 Naveen N. Rao
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®