From mboxrd@z Thu Jan  1 00:00:00 1970
From: Raghavendra K T <raghukt@linux.vnet.ibm.com>
Subject: Re: [PATCH RFC V2 3/5] kvm hypervisor : Add two hypercalls to support
 pv-ticketlock
Date: Mon, 24 Oct 2011 16:30:46 +0530
Message-ID: <4EA5455E.5090007@linux.vnet.ibm.com>
References: <20111023190307.16364.35381.sendpatchset@oc5400248562.ibm.com> <20111023190558.16364.2136.sendpatchset@oc5400248562.ibm.com> <1319450510.5660.6.camel@lappy>
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Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
	Greg Kroah-Hartman <gregkh@suse.de>,
	"H. Peter Anvin" <hpa@zytor.com>, Gleb Natapov <gleb@redhat.com>,
	Virtualization <virtualization@lists.linux-foundation.org>,
	Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
	x86@kernel.org, KVM <kvm@vger.kernel.org>,
	Dave Jiang <dave.jiang@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
	Xen <xen-devel@lists.xensource.com>,
	Sedat Dilek <sedat.dilek@gmail.com>,
	Yinghai Lu <yinghai@kernel.org>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	Ingo Molnar <mingo@redhat.com>, Avi Kivity <avi@redhat.com>,
	Rik van Riel <riel@redhat.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Suzuki Poulose <suzuki@linux.vnet.ibm.com>,
	Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
	Peter Zijlstra <peter
To: Sasha Levin <levinsasha928@gmail.com>
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On 10/24/2011 03:31 PM, Sasha Levin wrote:
> On Mon, 2011-10-24 at 00:35 +0530, Raghavendra K T wrote:
>> Add two hypercalls to KVM hypervisor to support pv-ticketlocks.
>>
>> +static void kvm_pv_kick_cpu_op(struct kvm *kvm, int cpu)
>> +{
>> +	struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, cpu);
>> +
>> +	if (vcpu) {
>> +		vcpu->kicked = 1;
>
> I'm not sure about it, but maybe we want a memory barrier over here?

Yes, Thanks for pointing this. Avi Kivity also pointed same. 'll add 
barrier() here.

>
>> +		wake_up_interruptible(&vcpu->wq);
>> +	}
>> +}