Re: question about splice performance

[Jan Engelhardt]

On Sunday 2008-05-25 17:12, Francis Moreau wrote:

>Hi,
>
>I did a really basic benchmark and was suprise about the results.
>
>$ echo 3 > /proc/sys/vm/drop_caches
>$ time  splice-cp  vmlinux /tmp/vmlinux
>
>real    0m10.158s
>user    0m0.002s
>sys     0m0.401s
>
>$ echo 3 > /proc/sys/vm/drop_caches
>$ time  cp  vmlinux /tmp/vmlinux
>
>real    0m10.590s
>user    0m0.017s
>sys     0m0.459s
>
>
>I was expecting splice-cp case to be faster.
>
>Could someone enlight me ?

Slow disk outweighs memory copying overhead. And 300 MB is quickly
transferred in idle systems.
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