Re: [PATCH 3/3] perf: bench: fix memcpy/memset output

From: Ingo Molnar
Date: Mon Dec 08 2014 - 05:25:44 EST



* Rabin Vincent <rabin.vincent@xxxxxxxx> wrote:

> The memcpy and memset benchmarks return bogus results when iterations >
> 0 because the iterations value is not taken into account when
> calculating the final result:
>
> $ perf bench mem memset --only-prefault --length 1GB --iterations 1
> # Running 'mem/memset' benchmark:
> # Copying 1GB Bytes ...
>
> 20.798669 GB/Sec (with prefault)
> $ perf bench mem memset --only-prefault --length 1GB --iterations 10
> # Running 'mem/memset' benchmark:
> # Copying 1GB Bytes ...
>
> 2.086576 GB/Sec (with prefault)
> $ perf bench mem memset --only-prefault --length 1GB --iterations 100
> # Running 'mem/memset' benchmark:
> # Copying 1GB Bytes ...
>
> 212.840917 MB/Sec (with prefault)
>
> Fix this.
>
> Signed-off-by: Rabin Vincent <rabin.vincent@xxxxxxxx>

Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>

Thanks,

Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/