fix CAHitNtupletGeneratorOnGPU in case of no hits

[mmusich]

solves #34659.

PR description:

Implementation follows @makortel comment #34659 (comment).

PR validation:

run successfully:

cmsDriver.py step3 --conditions auto:run3_hlt -s RAW2DIGI:RawToDigi_pixelOnly,RECO:reconstruction_pixelTrackingOnly,DQM:@pixelTrackingOnlyDQM --process reRECO --data --era Run3 --eventcontent RECO,MINIAOD,DQM --hltProcess reHLT --procModifiers pixelNtupletFit,gpu --scenario pp --datatier RECO,MINIAOD,DQMIO --filein file:/eos/cms/store/group/dpg_trigger/comm_trigger/TriggerStudiesGroup/FOG/CRUZET_2021_data/run_343762.root --no_exec

cmsRun step3_RAW2DIGI_RECO_DQM.py 

This needs further testing in a real HLT environment.

if this PR is a backport please specify the original PR and why you need to backport that PR:

N/A

[cmsbuild]

A new Pull Request was created by @mmusich (Marco Musich) for CMSSW_11_3_X.

It involves the following packages:

• RecoPixelVertexing/PixelTriplets (reconstruction)

@perrotta, @jpata, @cmsbuild, @slava77 can you please review it and eventually sign? Thanks.
@makortel, @felicepantaleo, @GiacomoSguazzoni, @JanFSchulte, @rovere, @VinInn, @mmusich, @mtosi, @dgulhan this is something you requested to watch as well.
@silviodonato, @dpiparo, @qliphy, @perrotta you are the release manager for this.

cms-bot commands are listed here

[mmusich]

type bug-fix

[mmusich]

enable gpu

[mmusich]

@cmsbuild, please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-434f78/17327/summary.html
COMMIT: fd06060
CMSSW: CMSSW_11_3_X_2021-07-25-0000/slc7_amd64_gcc900
Additional Tests: GPU
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/34684/17327/install.sh to create a dev area with all the needed externals and cmssw changes.

GPU Comparison Summary

Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 4
• DQMHistoTests: Total histograms compared: 9571
• DQMHistoTests: Total failures: 0
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 9571
• DQMHistoTests: Total skipped: 0
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 3 files compared)
• Checked 12 log files, 9 edm output root files, 4 DQM output files
• TriggerResults: no differences found

Comparison Summary

The workflows 140.53 have different files in step1_dasquery.log than the ones found in the baseline. You may want to check and retrigger the tests if necessary. You can check it in the "files" directory in the results of the comparisons

Summary:

• No significant changes to the logs found
• Reco comparison results: 1275 differences found in the comparisons
• DQMHistoTests: Total files compared: 38
• DQMHistoTests: Total histograms compared: 2878314
• DQMHistoTests: Total failures: 3672
• DQMHistoTests: Total nulls: 20
• DQMHistoTests: Total successes: 2874600
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: -45.707 KiB( 37 files compared)
• DQMHistoSizes: changed ( 140.53 ): -44.531 KiB Hcal/DigiRunHarvesting
• DQMHistoSizes: changed ( 140.53 ): -1.172 KiB RPC/DCSInfo
• DQMHistoSizes: changed ( 312.0 ): -0.004 KiB MessageLogger/Warnings
• Checked 160 log files, 37 edm output root files, 38 DQM output files
• TriggerResults: no differences found

[slava77]

@mmusich
is this not affecting 12_0_X/master at all?
Please elaborate why not (sorry, I did not fully follow the messages in #34659)

[mmusich]

@slava77

is this not affecting 12_0_X/master at all?

no, the same test (done by @tsusa) as in the PR description #34684 (comment) succeeds in master.

Please elaborate why not (sorry, I did not fully follow the messages in #34659)

My understanding from Matti's comment is that the problematic piece of code was changed in 12_0_X in #33371 (see #34659 (comment)).

[slava77]

+reconstruction

for #34684 fd06060

• code changes are in line with the PR description
• jenkins tests pass and comparisons with the baseline show no (relevant) differences

I suppose there is some interest to have a patch release with this fix soon.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_11_3_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_12_0_X is complete. This pull request will now be reviewed by the release team before it's merged. @silviodonato, @dpiparo, @qliphy, @perrotta (and backports should be raised in the release meeting by the corresponding L2)

[mmusich]

@gennai might want to comment here if this solves the issues on hilton too.

[makortel]

My understanding from Matti's comment is that the problematic piece of code was changed in 12_0_X in #33371 (see #34659 (comment)).

Right, I did not investigate any deeper what specifically in kernel_sharedHitCleaner causes problems for zero hits, or how #33371 would address that.

[perrotta]

+1