[Devel] [PATCH RHEL7 COMMIT] ms/kvm: add halt_attempted_poll to VCPU stats
Konstantin Khorenko
khorenko at virtuozzo.com
Tue Apr 19 03:22:50 PDT 2016
The commit is pushed to "branch-rh7-3.10.0-327.10.1.vz7.12.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-327.10.1.vz7.12.11
------>
commit f7383ba17c5add7f38bdcb9658577da54b778cfb
Author: Paolo Bonzini <pbonzini at redhat.com>
Date: Tue Apr 19 14:22:50 2016 +0400
ms/kvm: add halt_attempted_poll to VCPU stats
This new statistic can help diagnosing VCPUs that, for any reason,
trigger bad behavior of halt_poll_ns autotuning.
For example, say halt_poll_ns = 480000, and wakeups are spaced exactly
like 479us, 481us, 479us, 481us. Then KVM always fails polling and wastes
10+20+40+80+160+320+480 = 1110 microseconds out of every
479+481+479+481+479+481+479 = 3359 microseconds. The VCPU then
is consuming about 30% more CPU than it would use without
polling. This would show as an abnormally high number of
attempted polling compared to the successful polls.
Acked-by: Christian Borntraeger <borntraeger at de.ibm.com<
Reviewed-by: David Matlack <dmatlack at google.com>
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
(cherry picked from commit 62bea5bff486644ecf363fe8a1a2f6f32c614a49)
Conflicts:
arch/arm64/include/asm/kvm_host.h
arch/mips/kvm/mips.c
arch/s390/include/asm/kvm_host.h
arch/s390/kvm/kvm-s390.c
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov at virtuozzo.com>
---
arch/arm/include/asm/kvm_host.h | 1 +
arch/mips/include/asm/kvm_host.h | 1 +
arch/powerpc/include/asm/kvm_host.h | 1 +
arch/powerpc/kvm/book3s.c | 1 +
arch/powerpc/kvm/booke.c | 1 +
arch/s390/include/asm/kvm_host.h | 1 +
arch/s390/kvm/kvm-s390.c | 1 +
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/x86.c | 1 +
virt/kvm/kvm_main.c | 1 +
10 files changed, 10 insertions(+)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 34d4cd7..1467904 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -145,6 +145,7 @@ struct kvm_vm_stat {
struct kvm_vcpu_stat {
u32 halt_successful_poll;
+ u32 halt_attempted_poll;
u32 halt_wakeup;
};
diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 0767ce4..adc6b1f 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -96,6 +96,7 @@ struct kvm_vcpu_stat {
u32 break_inst_exits;
u32 flush_dcache_exits;
u32 halt_successful_poll;
+ u32 halt_attempted_poll;
u32 halt_wakeup;
};
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 0a94b9e..69c2389 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -112,6 +112,7 @@ struct kvm_vcpu_stat {
u32 dec_exits;
u32 ext_intr_exits;
u32 halt_successful_poll;
+ u32 halt_attempted_poll;
u32 halt_wakeup;
u32 dbell_exits;
u32 gdbell_exits;
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 7c36f66..f47b2cb 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -53,6 +53,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "ext_intr", VCPU_STAT(ext_intr_exits) },
{ "queue_intr", VCPU_STAT(queue_intr) },
{ "halt_successful_poll", VCPU_STAT(halt_successful_poll), },
+ { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll), },
{ "halt_wakeup", VCPU_STAT(halt_wakeup) },
{ "pf_storage", VCPU_STAT(pf_storage) },
{ "sp_storage", VCPU_STAT(sp_storage) },
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 4b41bf5..bc6220b 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -62,6 +62,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "dec", VCPU_STAT(dec_exits) },
{ "ext_intr", VCPU_STAT(ext_intr_exits) },
{ "halt_successful_poll", VCPU_STAT(halt_successful_poll) },
+ { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) },
{ "halt_wakeup", VCPU_STAT(halt_wakeup) },
{ "doorbell", VCPU_STAT(dbell_exits) },
{ "guest doorbell", VCPU_STAT(gdbell_exits) },
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 1f251a3..297b2c3 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -128,6 +128,7 @@ struct kvm_vcpu_stat {
u32 exit_validity;
u32 exit_instruction;
u32 halt_successful_poll;
+ u32 halt_attempted_poll;
u32 instruction_lctl;
u32 instruction_lctlg;
u32 exit_program_interruption;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 1e923bc..7775fe4 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -50,6 +50,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "exit_program_interruption", VCPU_STAT(exit_program_interruption) },
{ "exit_instr_and_program_int", VCPU_STAT(exit_instr_and_program) },
{ "halt_successful_poll", VCPU_STAT(halt_successful_poll) },
+ { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) },
{ "instruction_lctlg", VCPU_STAT(instruction_lctlg) },
{ "instruction_lctl", VCPU_STAT(instruction_lctl) },
{ "deliver_emergency_signal", VCPU_STAT(deliver_emergency_signal) },
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6bf2382..a73a3bb 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -694,6 +694,7 @@ struct kvm_vcpu_stat {
u32 nmi_window_exits;
u32 halt_exits;
u32 halt_successful_poll;
+ u32 halt_attempted_poll;
u32 halt_wakeup;
u32 request_irq_exits;
u32 irq_exits;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4b14f95..ca78e5e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -151,6 +151,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "nmi_window", VCPU_STAT(nmi_window_exits) },
{ "halt_exits", VCPU_STAT(halt_exits) },
{ "halt_successful_poll", VCPU_STAT(halt_successful_poll) },
+ { "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) },
{ "halt_wakeup", VCPU_STAT(halt_wakeup) },
{ "hypercalls", VCPU_STAT(hypercalls) },
{ "request_irq", VCPU_STAT(request_irq_exits) },
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index fb7a6b9..1fc1f12 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2000,6 +2000,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
if (vcpu->halt_poll_ns) {
ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns);
+ ++vcpu->stat.halt_attempted_poll;
do {
/*
* This sets KVM_REQ_UNHALT if an interrupt
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