Pileup summary info slimmer for MiniAOD

[lgray]

Per a line of investigation in the flashgg group I took a look at slimming the PileupSummaryInfos.
The results are quite nice when keeping the details only for the in-time bunch crossing, and then zeroing out all the vectors of track pTs and such for all others.

Bunch spacing, number of interactions, and true pileup mean are kept for all crossings.

You can see the benchmarking info here:
cms-analysis/flashgg#269 (comment)

It would seem a good idea just to include this in MiniAOD already since it saves 4.5kb/ev on TTBar 25ns (calculated from 100 events). Can only get better for more complex things.

@gpetruc @arizzi

[cmsbuild]

A new Pull Request was created by @lgray (Lindsey Gray) for CMSSW_7_5_X.

Pileup summary info slimmer for MiniAOD

It involves the following packages:

PhysicsTools/PatAlgos

@cmsbuild, @vadler, @monttj can you please review it and eventually sign? Thanks.
@rappoccio, @imarches, @ahinzmann, @acaudron, @mmarionncern, @jdolen, @nhanvtran, @schoef, @ferencek, @gpetruc, @mariadalfonso, @pvmulder, @TaiSakuma this is something you requested to watch as well.
You can sign-off by replying to this message having '+1' in the first line of your reply.
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@Degano you are the release manager for this.
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[lgray]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.

[cmsbuild]

+1
Tested at: 57fd6f1
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-10592/5274/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-10592/5274/summary.html

There are some workflows for which there are errors in the baseline:
50202.0 step 2
The results for the comparisons for these workflows could be incomplete
This means most likely that the IB is having errors in the relvals.The error does NOT come from this pull request

[lgray]

@sethzenz @musella You may be interested to follow.

[monttj]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_5_X IBs once checked with relvals in the development release cycle of CMSSW (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @Degano, @smuzaffar

[davidlange6]

+1