Re: CEPH Erasure Encoding + OSD Scalability

[Loic Dachary <loic@dachary.org>]

[-- Attachment #1: Type: text/plain, Size: 1543 bytes --]



On 11/12/2013 10:49, Andreas Joachim Peters wrote:> Hi Loic, 
> I am a little bit confused which kind of tool you actually want. You want a simple benchmark to check for degradation or you want a full profiler tool?
> 

I was not sure, hence the confusion.

> Most of the external tools have the problem that you measure the whole thing including buffer allocation and initialization. We probably don't want to measure how long it takes to allocate memory and write random numbers into it. 
> 
> I would just o:
> 
> < prepare memory>
> <take CPU/realtime>
> < run algorithm >
> <take CPU/realtime>
> < print result>
> 

Ok, I'll do that. 

I'm glad I learnt about the other tools in the process, even if only to conclude that they are not needed. 

Cheers

> Now one can also add to run the perf-stat tool after <prepare memory> and start it from within the test program pointing to the PID running <run alogorithm>, so the benchmark would be:
> 
> < prepare memory>
> < take CPU/realtime>
> < fork=>"perf stat -p <mypid>";
> < run algorithm n times>
> < take CPU/realtime>
> < SIGINT to fork>
> < print results>
> 
> As an extension one could also add to have <run algorithm> with <n> threads in a thread pool.
> 
> Cheers Andreas.
> 
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

-- 
Loïc Dachary, Artisan Logiciel Libre


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 263 bytes --]