* [PATCH v2] KVM: Don't shrink/grow vCPU halt_poll_ns if host side polling is disabled
@ 2019-09-29 1:06 Wanpeng Li
2019-10-08 1:07 ` Wanpeng Li
2019-10-08 12:11 ` Paolo Bonzini
0 siblings, 2 replies; 3+ messages in thread
From: Wanpeng Li @ 2019-09-29 1:06 UTC (permalink / raw)
To: linux-kernel, kvm
Cc: Paolo Bonzini, Radim Krčmář,
Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, Marcelo Tosatti
From: Wanpeng Li <wanpengli@tencent.com>
Don't waste cycles to shrink/grow vCPU halt_poll_ns if host
side polling is disabled.
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
---
v1 -> v2:
* fix coding style
virt/kvm/kvm_main.c | 29 ++++++++++++++++-------------
1 file changed, 16 insertions(+), 13 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index e6de315..9d5eed9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2359,20 +2359,23 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
kvm_arch_vcpu_unblocking(vcpu);
block_ns = ktime_to_ns(cur) - ktime_to_ns(start);
- if (!vcpu_valid_wakeup(vcpu))
- shrink_halt_poll_ns(vcpu);
- else if (halt_poll_ns) {
- if (block_ns <= vcpu->halt_poll_ns)
- ;
- /* we had a long block, shrink polling */
- else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
+ if (!kvm_arch_no_poll(vcpu)) {
+ if (!vcpu_valid_wakeup(vcpu)) {
shrink_halt_poll_ns(vcpu);
- /* we had a short halt and our poll time is too small */
- else if (vcpu->halt_poll_ns < halt_poll_ns &&
- block_ns < halt_poll_ns)
- grow_halt_poll_ns(vcpu);
- } else
- vcpu->halt_poll_ns = 0;
+ } else if (halt_poll_ns) {
+ if (block_ns <= vcpu->halt_poll_ns)
+ ;
+ /* we had a long block, shrink polling */
+ else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
+ shrink_halt_poll_ns(vcpu);
+ /* we had a short halt and our poll time is too small */
+ else if (vcpu->halt_poll_ns < halt_poll_ns &&
+ block_ns < halt_poll_ns)
+ grow_halt_poll_ns(vcpu);
+ } else {
+ vcpu->halt_poll_ns = 0;
+ }
+ }
trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu));
kvm_arch_vcpu_block_finish(vcpu);
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] KVM: Don't shrink/grow vCPU halt_poll_ns if host side polling is disabled
2019-09-29 1:06 [PATCH v2] KVM: Don't shrink/grow vCPU halt_poll_ns if host side polling is disabled Wanpeng Li
@ 2019-10-08 1:07 ` Wanpeng Li
2019-10-08 12:11 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Wanpeng Li @ 2019-10-08 1:07 UTC (permalink / raw)
To: LKML, kvm
Cc: Paolo Bonzini, Radim Krčmář,
Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, Marcelo Tosatti
ping,
On Sun, 29 Sep 2019 at 09:07, Wanpeng Li <kernellwp@gmail.com> wrote:
>
> From: Wanpeng Li <wanpengli@tencent.com>
>
> Don't waste cycles to shrink/grow vCPU halt_poll_ns if host
> side polling is disabled.
>
> Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
> Cc: Marcelo Tosatti <mtosatti@redhat.com>
> Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
> ---
> v1 -> v2:
> * fix coding style
>
> virt/kvm/kvm_main.c | 29 ++++++++++++++++-------------
> 1 file changed, 16 insertions(+), 13 deletions(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index e6de315..9d5eed9 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2359,20 +2359,23 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
> kvm_arch_vcpu_unblocking(vcpu);
> block_ns = ktime_to_ns(cur) - ktime_to_ns(start);
>
> - if (!vcpu_valid_wakeup(vcpu))
> - shrink_halt_poll_ns(vcpu);
> - else if (halt_poll_ns) {
> - if (block_ns <= vcpu->halt_poll_ns)
> - ;
> - /* we had a long block, shrink polling */
> - else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
> + if (!kvm_arch_no_poll(vcpu)) {
> + if (!vcpu_valid_wakeup(vcpu)) {
> shrink_halt_poll_ns(vcpu);
> - /* we had a short halt and our poll time is too small */
> - else if (vcpu->halt_poll_ns < halt_poll_ns &&
> - block_ns < halt_poll_ns)
> - grow_halt_poll_ns(vcpu);
> - } else
> - vcpu->halt_poll_ns = 0;
> + } else if (halt_poll_ns) {
> + if (block_ns <= vcpu->halt_poll_ns)
> + ;
> + /* we had a long block, shrink polling */
> + else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
> + shrink_halt_poll_ns(vcpu);
> + /* we had a short halt and our poll time is too small */
> + else if (vcpu->halt_poll_ns < halt_poll_ns &&
> + block_ns < halt_poll_ns)
> + grow_halt_poll_ns(vcpu);
> + } else {
> + vcpu->halt_poll_ns = 0;
> + }
> + }
>
> trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu));
> kvm_arch_vcpu_block_finish(vcpu);
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] KVM: Don't shrink/grow vCPU halt_poll_ns if host side polling is disabled
2019-09-29 1:06 [PATCH v2] KVM: Don't shrink/grow vCPU halt_poll_ns if host side polling is disabled Wanpeng Li
2019-10-08 1:07 ` Wanpeng Li
@ 2019-10-08 12:11 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2019-10-08 12:11 UTC (permalink / raw)
To: Wanpeng Li, linux-kernel, kvm
Cc: Radim Krčmář,
Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, Marcelo Tosatti
On 29/09/19 03:06, Wanpeng Li wrote:
> From: Wanpeng Li <wanpengli@tencent.com>
>
> Don't waste cycles to shrink/grow vCPU halt_poll_ns if host
> side polling is disabled.
>
> Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
> Cc: Marcelo Tosatti <mtosatti@redhat.com>
> Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
> ---
> v1 -> v2:
> * fix coding style
>
> virt/kvm/kvm_main.c | 29 ++++++++++++++++-------------
> 1 file changed, 16 insertions(+), 13 deletions(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index e6de315..9d5eed9 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2359,20 +2359,23 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
> kvm_arch_vcpu_unblocking(vcpu);
> block_ns = ktime_to_ns(cur) - ktime_to_ns(start);
>
> - if (!vcpu_valid_wakeup(vcpu))
> - shrink_halt_poll_ns(vcpu);
> - else if (halt_poll_ns) {
> - if (block_ns <= vcpu->halt_poll_ns)
> - ;
> - /* we had a long block, shrink polling */
> - else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
> + if (!kvm_arch_no_poll(vcpu)) {
> + if (!vcpu_valid_wakeup(vcpu)) {
> shrink_halt_poll_ns(vcpu);
> - /* we had a short halt and our poll time is too small */
> - else if (vcpu->halt_poll_ns < halt_poll_ns &&
> - block_ns < halt_poll_ns)
> - grow_halt_poll_ns(vcpu);
> - } else
> - vcpu->halt_poll_ns = 0;
> + } else if (halt_poll_ns) {
> + if (block_ns <= vcpu->halt_poll_ns)
> + ;
> + /* we had a long block, shrink polling */
> + else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
> + shrink_halt_poll_ns(vcpu);
> + /* we had a short halt and our poll time is too small */
> + else if (vcpu->halt_poll_ns < halt_poll_ns &&
> + block_ns < halt_poll_ns)
> + grow_halt_poll_ns(vcpu);
> + } else {
> + vcpu->halt_poll_ns = 0;
> + }
> + }
>
> trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu));
> kvm_arch_vcpu_block_finish(vcpu);
>
Queued, thanks.
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-10-08 1:07 ` Wanpeng Li
2019-10-08 12:11 ` Paolo Bonzini
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