sPHENIX discussion of software

[Hugo Pereira Da Costa <hugo.pereira-da-costa AT cea.fr>]

Hi Christoph,

Thanks for the investigation.

If no one else volunteer I can work on replacing the 
std::map<cluster_key, cluster_ptr> by a vector as discussed in another 
email. I don't expect it to be more than a day or two of work.

Maybe we can discuss this on monday ?

Hugo


On 4/8/22 05:46, Christof E Roland via sPHENIX-software-l wrote:
> Hi,
>
> following our discussion on Tuesday i did a quick study on our storage 
> containers, especially the ones using maps, i.e.  the hitsetcontainer.
> The hitsetcontainer is the construct storing what is, from the reco software 
> point of view, the closest representation of raw data we have defined.
>
> I filled the hitsetcontainer with either 5 k or ~5.5 million fake hits per 
> event and looked at the evolution of the memory footprint of the jobs using
> the prmon tool. From the difference between the low and high occupancy case I 
> canlculate the job memory "price tag" of storing a hit, i.e. 3 unint32 - 12 
> bytes.
>
> Storing 5 million extra hits in a std map increases the job memory by 0.5GB. 
> This corresponds to a ~100byte effective memory price tag including all the 
> overhead
> and pre allocated memory around stl maps.
>
> Using TObjArrays its about 60 byte
>
> For stl vectors its ~14 which, given the precision with which you can read 
> off the GB job memory scale in prmon, is equal to the 12 bytes you expect.
>
> I guess we should investigate to which extend we can get rid of maps wherever 
> we can.
>
> Cheers
>
>     Christof
>
>
>
> _______________________________________________
> sPHENIX-software-l mailing list
> sPHENIX-software-l AT lists.bnl.gov
> https://lists.bnl.gov/mailman/listinfo/sphenix-software-l