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SubjectRe: question about splice performance
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 ?

If you drop caches you are not measuring splice speed.

Use ramfs for your tests (guarantees data is in cache) instead.

Jeff





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