Re: [PATCH 1/2] benchtests: Memory walking benchmark for memcpy

[Victor Rodriguez <vm dot rod25 at gmail dot com>]

On Wed, Oct 4, 2017 at 5:49 PM, Carlos O'Donell <carlos@redhat.com> wrote:
> On 10/04/2017 03:45 PM, Victor Rodriguez wrote:
>> On Wed, Oct 4, 2017 at 5:19 PM, Carlos O'Donell <carlos@redhat.com> wrote:
>>> On 10/03/2017 11:53 PM, Siddhesh Poyarekar wrote:
>>>> On Friday 22 September 2017 05:29 AM, Siddhesh Poyarekar wrote:
>>>>> On Thursday 21 September 2017 11:59 PM, Carlos O'Donell wrote:
>>>>>> I like the idea, and the point that the other benchmark eventually degrades
>>>>>> into measuring L1 performance an interesting insight.
>>>>>>
>>>>>> I do not like that it produces total data rate not time taken per execution.
>>>>>> Why the change? If time taken per execution was OK before, why not here?
>>>>>
>>>>> That is because it seems more natural to express string function
>>>>> performance by the rate at which it processes data than the time it
>>>>> takes to execute.  It also makes comparison across sizes a bit
>>>>> interesting, i.e. the data rate for processing 1MB 32 bytes at a time vs
>>>>> 128 bytes at a time.
>>>>>
>>>>> The fact that "twice as fast" sounds better than "takes half the time"
>>>>> is an added bonus :)
>>>>
>>>> Carlos, do you think this is a reasonable enough explanation?  I'll fix
>>>> up the output in a subsequent patch so that it has a 'throughput'
>>>> property that the post-processing scripts can read without needing the
>>>> additional argument in 2/2.
>>>
>>> As the subsystem maintainer I defer to your choice here. I don't have a
>>> strong opinion, other than a desire for conformity of measurements to
>>> avoid confusion. If I could say anything, consider the consumer and make
>>> sure the data is tagged such that a consumer can determine if it is time
>>> or throughput.
>>>
>>> --
>>> Cheers,
>>> Carlos.
>>
>> Quick question , do you think it might be good idea to add this test
>> into the prhonix glibc bench :
>>
>> https://openbenchmarking.org/test/pts/glibc-bench
>> https://openbenchmarking.org/innhold/cac2836cd5dbb8ae279f8a5e7b0896272e82dc76
>>
>> If so, let me know so I can work on add it
>
> As a volunteer I appreciated any work you may wish to do for the project.
>
> Certainly, if you find it valuable to keep the pts/glibc-bench in sync
> with glibc benchtests/ then it sounds like a good idea to update it
> regularly based on the glibc changes.

Sure, happy to help comunity
>
> What is your impression of how pts/glibc-bench is being used?
>

The section: " Recent Results With This Test " shows that it has been
used to measure things like :

Linux 4.14-rc1 vs. Linux 4.13 Kernel Benchmarks
https://openbenchmarking.org/result/1709186-TY-LINUX414R23

as well as other core CPU systems

So in my humble opinion, i think is getting a lot of attraction

There is still work that need to be done but is good to have a way to
measure the performance with Phoronix framework

Regards

Victor R
> --
> Cheers,
> Carlos.