Re: [PATCH v4 4/5] KVM: LAPIC: Delay trace advance expire delta

2019-05-20 Thread Wanpeng Li
On Mon, 20 May 2019 at 19:41, Paolo Bonzini wrote: > > On 20/05/19 13:36, Wanpeng Li wrote: > >> Hmm, yeah, that makes sense. The location of the tracepoint is a bit > >> weird, but I guess we can add a comment in the code. > > Do you need me to post a new patchset? :) > > No problem. The final

Re: [PATCH v4 4/5] KVM: LAPIC: Delay trace advance expire delta

2019-05-20 Thread Paolo Bonzini
On 20/05/19 13:36, Wanpeng Li wrote: >> Hmm, yeah, that makes sense. The location of the tracepoint is a bit >> weird, but I guess we can add a comment in the code. > Do you need me to post a new patchset? :) No problem. The final patch that I committed is this: diff --git a/arch/x86/kvm/lapic.

Re: [PATCH v4 4/5] KVM: LAPIC: Delay trace advance expire delta

2019-05-20 Thread Wanpeng Li
On Mon, 20 May 2019 at 19:33, Paolo Bonzini wrote: > > On 20/05/19 13:22, Wanpeng Li wrote: > >> > >> We would like to move wait_lapic_expire() just before vmentry, which would > >> place wait_lapic_expire() again inside the extended quiescent state. Drop > >> the tracepoint, but add instead anot

Re: [PATCH v4 4/5] KVM: LAPIC: Delay trace advance expire delta

2019-05-20 Thread Paolo Bonzini
On 20/05/19 13:22, Wanpeng Li wrote: >> >> We would like to move wait_lapic_expire() just before vmentry, which would >> place wait_lapic_expire() again inside the extended quiescent state. Drop >> the tracepoint, but add instead another one that can be useful and where >> we can check the status

Re: [PATCH v4 4/5] KVM: LAPIC: Delay trace advance expire delta

2019-05-20 Thread Wanpeng Li
On Mon, 20 May 2019 at 19:14, Paolo Bonzini wrote: > > On 20/05/19 10:18, Wanpeng Li wrote: > > From: Wanpeng Li > > > > wait_lapic_expire() call was moved above guest_enter_irqoff() because of > > its tracepoint, which violated the RCU extended quiescent state invoked > > by guest_enter_irqoff()

Re: [PATCH v4 4/5] KVM: LAPIC: Delay trace advance expire delta

2019-05-20 Thread Paolo Bonzini
On 20/05/19 10:18, Wanpeng Li wrote: > From: Wanpeng Li > > wait_lapic_expire() call was moved above guest_enter_irqoff() because of > its tracepoint, which violated the RCU extended quiescent state invoked > by guest_enter_irqoff()[1][2]. This patch simply moves the tracepoint > below guest_e

[PATCH v4 4/5] KVM: LAPIC: Delay trace advance expire delta

2019-05-20 Thread Wanpeng Li
From: Wanpeng Li wait_lapic_expire() call was moved above guest_enter_irqoff() because of its tracepoint, which violated the RCU extended quiescent state invoked by guest_enter_irqoff()[1][2]. This patch simply moves the tracepoint below guest_exit_irqoff() in vcpu_enter_guest(). Snapshot the