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processors:

Xeon E5430 8 cores

speed 2.66GHZ

architecture EM64T

OS:

SLC5.4, i686, X86_64

test modes:

native mode (64bit/64bit)

BOSS

6.5.5

Event type:

  • simulation
Inclusive MC jobs(single run, jpsi,psip,psipp) : 10 M
Exclusive MC jobs (multiple runs, jpsi,psip,psipp) : 2M
  • simulation-reconstruction
  • real-reconstruction

Stability check:

  • More than 10M events used
  • Problems:
    • 6 dead loops in EMC simulation are found among 10M events
    • Dead locks happened in lustre system when reading random trigger files in multi MC jobs with single run, which is caused by a bug in lustre current 64-bit client version
  • Status:
    • Problems are fixed
    • no segment fault and no broken of any kind are found so far

Cpu time(50,000 events)

  simu simu-reco real-reco simu-ana real-ana
64-bit 0.945466 0.214966 0.122502 0.008806 0.001074
32-bit 1.091518 0.431005 0.245715 0.017034 0.002753
comparison ~13% ~50% ~50% ~48% 61%
  • Event process rate increases very significantly although varies among different applications and different data
    • Simulation speed increases about 13%
    • Reconstruction speed increases about 50%
    • Analysis speed increases about 50%
    • Reconstruction and analysis benefit a lot, twice faster than 32-bit
  • Such increases are proved by further tests:

Memory usage(20,000 events)

  • There are two measures of memory to be monitoring here: VSize, RSS
  • The process is to be monitoring: simulation, simulation-reconstruction, real-reconstruction
  • Memory consumed for 64-bit BOSS nearly twice larger than that of 32-bit BOSS :
    • It also varies among different processes and different data
    • Virtual memory : ~1500MB(simu), ~1400MB(rec)
    • Resident memory : ~600MB(simu), ~500MB(rec)
RSS simu simu-reco real-reco
64-bit 605.8 534.8 456.0
32-bit 384.7 388.2 320.9
comparison ~57.5% ~37.8% ~42.1%
  • Some reasons for significant memory increases of 64-bit applications
    • Certain data types (e.g. pointers, size_t) increase in size, resulting in larger data structures
    • Alignment/padding of data structures are larger at 64bit
    • Code size in libraries increase at 64bit
    • Administrative overhead and alignment for objects created in the heap typically increases
    • Conclusions:
      • Memory consumption are almost doubled
      • It is reasonable and still in an acceptable scope

Memory leaks(20,000 events)

  • Processes:
    • simu, simu-reco, real-reco
  • Leaks are found both in 32-bit systems and 64-bit systems
    • Leaks are also enlarged in 64-bit
    • Simulation about 4.54KB/event
    • Reconstruction about 7.37KB/event
  • Conclusions:
    • Memory leakage is not obvious
    • It is acceptable

-- ZhangXiaomei - 2011-03-02

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Topic revision: r2 - 2011-03-16 - ZhangXiaomei
 
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