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Date: Mon, 02 Apr 2012 17:45:27 +0530
From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Organization: IBM
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To: Avi Kivity <avi@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
CC: Alan Meadows <alan.meadows@gmail.com>, Ingo Molnar <mingo@elte.hu>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Peter Zijlstra <peterz@infradead.org>,
        the arch/x86 maintainers <x86@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Marcelo Tosatti <mtosatti@redhat.com>, KVM <kvm@vger.kernel.org>,
        Andi Kleen <andi@firstfloor.org>,
        Xen Devel <xen-devel@lists.xensource.com>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Virtualization <virtualization@lists.linux-foundation.org>,
        Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
        Stephan Diestelhorst <stephan.diestelhorst@amd.com>,
        Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
        Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
        Attilio Rao <attilio.rao@citrix.com>
Subject: Re: [PATCH RFC V6 0/11] Paravirtualized ticketlocks
References: <20120321102041.473.61069.sendpatchset@codeblue.in.ibm.com> <4F707C5F.1000905@redhat.com>	<4F716E31.3000803@linux.vnet.ibm.com> <CAMy5W3foop40+R1RLv_JPhnO5ZmV90uMmNERYY-e3QCeaJfqLw@mail.gmail.com> <4F73568D.7000703@linux.vnet.ibm.com> <4F743247.5080407@redhat.com> <4F74A405.2040609@linux.vnet.ibm.com> <4F7585EE.7060203@linux.vnet.ibm.com> <4F7855A1.80107@redhat.com> <4F785CC9.7070204@linux.vnet.ibm.com> <4F785DCF.7020809@redhat.com> <4F7976B6.5050000@linux.vnet.ibm.com>
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On 04/02/2012 03:21 PM, Raghavendra K T wrote:
> On 04/01/2012 07:23 PM, Avi Kivity wrote:
>  > On 04/01/2012 04:48 PM, Raghavendra K T wrote:
>  >>>> I have patch something like below in mind to try:
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 5127668..3fa912a 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -1557,12 +1557,17 @@ void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
> mark_page_dirty_in_slot(kvm, memslot, gfn);
> }
>
> +#define YIELD_THRESHOLD 2048
> +static void kvm_vcpu_try_yield_to(struct kvm_vcpu *me);
> /*
> * The vCPU has executed a HLT instruction with in-kernel mode enabled.
> */
> void kvm_vcpu_block(struct kvm_vcpu *vcpu)
> {
[...]
> + if (loop_count++ % YIELD_THRESHOLD)
> + schedule();
> + else
> + kvm_vcpu_try_yield_to(vcpu);
> }
>
> +static void kvm_vcpu_try_yield(struct kvm_vcpu *me)

yes, it is kvm_vcpu_try_yield_to. had changed the name just before
sending. sorry.