Add three log histogram stats to record the distribution of time spent
on successful polling, failed polling and VCPU wait.
halt_poll_success_hist: Distribution of spent time for a successful poll.
halt_poll_fail_hist: Distribution of spent time for a failed poll.
halt_wait_hist: Distribution of time a VCPU has spent on waiting.
Signed-off-by: Jing Zhang <jingzhangos@xxxxxxxxxx>
---
arch/powerpc/kvm/book3s_hv.c | 16 ++++++++++++++--
include/linux/kvm_host.h | 8 +++++++-
include/linux/kvm_types.h | 5 +++++
virt/kvm/kvm_main.c | 12 ++++++++++++
4 files changed, 38 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 813ca155561b..6d63c8e6d4f0 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4146,17 +4146,29 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
if (do_sleep) {
vc->runner->stat.generic.halt_wait_ns +=
ktime_to_ns(cur) - ktime_to_ns(start_wait);
+ KVM_STATS_LOG_HIST_UPDATE(
+ vc->runner->stat.generic.halt_wait_hist,
+ ktime_to_ns(cur) - ktime_to_ns(start_wait));
/* Attribute failed poll time */
- if (vc->halt_poll_ns)
+ if (vc->halt_poll_ns) {
vc->runner->stat.generic.halt_poll_fail_ns +=
ktime_to_ns(start_wait) -
ktime_to_ns(start_poll);
+ KVM_STATS_LOG_HIST_UPDATE(
+ vc->runner->stat.generic.halt_poll_fail_hist,
+ ktime_to_ns(start_wait) -
+ ktime_to_ns(start_poll));
+ }
} else {
/* Attribute successful poll time */
- if (vc->halt_poll_ns)
+ if (vc->halt_poll_ns) {
vc->runner->stat.generic.halt_poll_success_ns +=
ktime_to_ns(cur) -
ktime_to_ns(start_poll);
+ KVM_STATS_LOG_HIST_UPDATE(
+ vc->runner->stat.generic.halt_poll_success_hist,
+ ktime_to_ns(cur) - ktime_to_ns(start_poll));
+ }
}
/* Adjust poll time */
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 9b773fef7bba..b67f01f61840 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1403,7 +1403,13 @@ struct _kvm_stats_desc {
STATS_DESC_COUNTER(VCPU_GENERIC, halt_wakeup), \
STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_success_ns), \
STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns), \
- STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_wait_ns)
+ STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_wait_ns), \
+ STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_poll_success_hist, \
+ HALT_POLL_HIST_COUNT), \
+ STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_hist, \
+ HALT_POLL_HIST_COUNT), \
+ STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_wait_hist, \
+ HALT_POLL_HIST_COUNT)
extern struct dentry *kvm_debugfs_dir;
diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
index 291ef55125b2..de7fb5f364d8 100644
--- a/include/linux/kvm_types.h
+++ b/include/linux/kvm_types.h
@@ -76,6 +76,8 @@ struct kvm_mmu_memory_cache {
};
#endif
+#define HALT_POLL_HIST_COUNT 32
+
struct kvm_vm_stat_generic {
u64 remote_tlb_flush;
};
@@ -88,6 +90,9 @@ struct kvm_vcpu_stat_generic {
u64 halt_poll_success_ns;
u64 halt_poll_fail_ns;
u64 halt_wait_ns;
+ u64 halt_poll_success_hist[HALT_POLL_HIST_COUNT];
+ u64 halt_poll_fail_hist[HALT_POLL_HIST_COUNT];
+ u64 halt_wait_hist[HALT_POLL_HIST_COUNT];
};
#define KVM_STATS_NAME_SIZE 48
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index af9bcb50fdd4..717006de17e7 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3166,13 +3166,23 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
++vcpu->stat.generic.halt_successful_poll;
if (!vcpu_valid_wakeup(vcpu))
++vcpu->stat.generic.halt_poll_invalid;
+
+ KVM_STATS_LOG_HIST_UPDATE(
+ vcpu->stat.generic.halt_poll_success_hist,
+ ktime_to_ns(ktime_get()) -
+ ktime_to_ns(start));
goto out;
}
cpu_relax();
poll_end = cur = ktime_get();
} while (kvm_vcpu_can_poll(cur, stop));
+
+ KVM_STATS_LOG_HIST_UPDATE(
+ vcpu->stat.generic.halt_poll_fail_hist,
+ ktime_to_ns(ktime_get()) - ktime_to_ns(start));
}
+
prepare_to_rcuwait(&vcpu->wait);
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
@@ -3188,6 +3198,8 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
if (waited) {
vcpu->stat.generic.halt_wait_ns +=
ktime_to_ns(cur) - ktime_to_ns(poll_end);
+ KVM_STATS_LOG_HIST_UPDATE(vcpu->stat.generic.halt_wait_hist,
+ ktime_to_ns(cur) - ktime_to_ns(poll_end));
}
out:
kvm_arch_vcpu_unblocking(vcpu);
--
2.32.0.554.ge1b32706d8-goog
