Re: [patch 0/3] kvm tool: Serial emulation overhaul

From: Avi Kivity
Date: Mon Dec 12 2011 - 13:20:00 EST


On 12/12/2011 01:19 PM, Pekka Enberg wrote:
> On Sun, Dec 11, 2011 at 5:53 PM, Ingo Molnar <mingo@xxxxxxx> wrote:
> > Okay, but look at it from another angle: the top output i
> > generate is about 300k characters. 5000 msecs to execute it
> > means 16 usecs overhead per character - or about 50k cycles - on
> > a top of the class x86 CPU.
>
> I'm seeing 1.5 usecs per character for this little benchmark:
>
>


No interrupts, right? Things look differently with one interrupt per
character and none. Try running kvm_stat with your benchmark and with a
guest kernel flooding the serial port.

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

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