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From: Avi Kivity <avi@redhat.com>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: kvm@vger.kernel.org, Gleb Natapov <gleb@redhat.com>,
	Ingo Molnar <mingo@elte.hu>,
	Peter Zijlstra <peter@programming.kicks-ass.net>
Subject: Re: KVM: x86: use smp_send_reschedule in kvm_vcpu_kick
Date: Mon, 09 Mar 2009 12:17:26 +0200	[thread overview]
Message-ID: <49B4ECB6.8060505@redhat.com> (raw)
In-Reply-To: <20090303001405.GA5889@amt.cnet>

Marcelo Tosatti wrote:
> KVM uses a function call IPI to cause the exit of a guest running on a
> physical cpu. For virtual interrupt notification there is no need to
> wait on IPI receival, or to execute any function.
>
> This is exactly what the reschedule IPI does, without the overhead
> of function IPI. So use it instead of smp_call_function_single in
> kvm_vcpu_kick.
>
> Also change the "guest_mode" variable to a bit in vcpu->requests, and
> use that to collapse multiple IPI's that would be issued between the
> first one and zeroing of guest mode.
>
> This allows kvm_vcpu_kick to called from interrupt context.
>   

Looks good.  The only worry I have is that we depend on 
smp_reschedule_interrupt() being a no-op.  I guess that's a reasonable 
assumption though.

-- 
error compiling committee.c: too many arguments to function


  parent reply	other threads:[~2009-03-09 10:17 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-03  0:14 Marcelo Tosatti
2009-03-03  7:53 ` Zhang, Xiantao
2009-03-03 13:25   ` Marcelo Tosatti
2009-03-03 13:25     ` Gleb Natapov
2009-03-03 13:56       ` Marcelo Tosatti
2009-03-09 10:17 ` Avi Kivity [this message]
2009-03-09 10:58   ` KVM: " Ingo Molnar
2009-03-09 11:09     ` Peter Zijlstra
2009-03-09 23:23       ` Marcelo Tosatti
2009-03-10  8:01         ` Avi Kivity
2009-03-12  2:31           ` Zhang, Xiantao
2009-03-12  7:06             ` Avi Kivity
2009-03-12 11:04             ` Gleb Natapov
2009-03-13  2:15               ` Zhang, Xiantao
2009-03-19  7:38                 ` Gleb Natapov
2009-03-19  7:56                   ` Zhang, Xiantao
2009-03-19  8:11                     ` Gleb Natapov

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