Re: [PATCH v4 00/20] xen/arm64: Add support for 64KB page in Linux

[Julien Grall]

Hi Roger,

On 14/09/15 13:08, Roger Pau Monnà wrote:
> Well, absolute numbers together with the standard deviation are IMHO the
> best way to provide those figures (ie: see ministat(1) output for
> example), but percentages should also be fine.
> 
> I'm just interested in knowing the performance difference between having
> this patches applied or not when using 4KB pages on the frontend and the
> backend.

I did some benchmark:
	DOM0: 1 VCPU, 4G of RAM based on 4.3-rc1 without this series
	GUEST: 4 VPUs, 4G of RAM, second disk associate to a nullbk device

I used fio with the following options

42sh> fio --name=test --ioengine=libaio --rw=read --numjobs=8 \
--iodepth=32 --time_based=1 --runtime=30 --bs=4KB \
--filename=/dev/xvdb--direct=1 --group_reporting=1 --iodepth_batch=16

The guest is also based on 4.3-rc1 with and without the series.

The overhead with my series is about 0.56%.

Regards,

-- 
Julien Grall
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