sPHENIX tracking discussion

[pinkenburg <pinkenburg AT bnl.gov>]

    HI Tony,
    
    I ran callgrind over it, by adding macros one can restrict it to
    small parts of the code:
    https://wiki.sphenix.bnl.gov/index.php/Tools#Advanced_Usage
    
    It spends 77% of its time in 
    
    void
    TrkrHitTruthAssocv1::removeAssoc(const TrkrDefs::hitsetkey
    hitsetkey, const TrkrDefs::hitkey hitkey)
    
     which is 6 lines of code removing an entry from a multimap. Does
    anyone know how to speed this up? This is by far the most severe
    limitation on how many events we can run through the simulation
    chain till the run starts.
    
    Chris

On 9/4/2022 11:29 AM, Anthony Frawley wrote:

        Hi Chris,
      
        
      
      
        This may be due to a change I made to the TPC digitizer to
        properly handle non-zero bunch crossings. It was merged on
        August 4, I think. The digitizer previously assumed that if a
        hit had a nominal z position that was negative, it was read out
        on the south side of the TPC. When I switched to storing TPC
        time of arrival, I also modified the digitizer code to not make
        that assumption - the assumption is just wrong if the crossing
        number is not zero. Now the hits are assigned during hit
        reconstruction to the readout direction corresponding to their
        true location in the TPC, and they keep that forever.
      
        
      
      
        The result is that the digitizer previously looped over half of
        the TPC time bin range for a given hit. The half was chosen
        based on its nominal z position. Now it loops over the entire
        range of time(z) bins, so the loop is twice as long. This change
        is needed to get the correct response for out of time events,
        which occur even in triggered Au+Au running.
        
      
      
        
      
      
        It is very possible that the digitization loop over time bins
        could be better optimized.
        
      
      
        
      
      
        Tony

---

From: sPHENIX-tracking-l <sphenix-tracking-l-bounces AT lists.bnl.gov> on behalf of pinkenburg via sPHENIX-tracking-l <sphenix-tracking-l AT lists.bnl.gov>
Sent: Sunday, September 4, 2022 9:24 AM
To: sphenix-tracking <sphenix-tracking-l AT lists.bnl.gov>
Subject: [Sphenix-tracking-l] PHG4TpcDigitizer timing

 

Hi folks,

until fairly recently the clustering (which I tend to call electron
drift) took about as much time as the G4 simulations themselves. As of
recently the time of this pass has increased by at least a factor of 2
and I see hijing jobs with 400 MinBias events exceeding the 3 day limit
which evicts those jobs so we only get calorimeter clusters from these
sims. You can see the timers in a log from a jobs which finished today:
/direct/sphenix+u/sphnxpro/MDC2/submit/JS_pp200_signal/pass3trk_embed/condor/log/condor_Jet30-0000000040-00175.out

The PHG4TpcDigitizer is by far the biggest contributor now.

Chris

--
*************************************************************

Christopher H. Pinkenburg       ;    pinkenburg AT bnl.gov
                                ;    https://urldefense.com/v3/__http://www.phenix.bnl.gov/*pinkenbu__;fg!!PhOWcWs!xe8FYrNmsJulJp9oBu13WteweyGO1vSpcnB1taOCGMEm8CZmAW-zqiaFMW5F9QITuO1kZ3Z6bazeMWDFX4Uz7NQaAkyskfRdMw$ 

Brookhaven National Laboratory  ;    phone: (631) 344-5692
Physics Department Bldg 510 C   ;    fax:   (631) 344-3253
Upton, NY 11973-5000

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-- 
*************************************************************

Christopher H. Pinkenburg	;    pinkenburg AT bnl.gov
				;    http://www.phenix.bnl.gov/~pinkenbu

Brookhaven National Laboratory	;    phone: (631) 344-5692
Physics Department Bldg 510 C	;    fax:   (631) 344-3253
Upton, NY 11973-5000

*************************************************************

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