Repository navigation
Conversation
This frees memory in the TPC digitizer that is not needed after the recalculation of the scaled distortions. - The digitizer only uses the global distortions of the main map. - The global corrections of the main and the derivative map are now released after the recalculation. https://its.cern.ch/jira/browse/O2-7309 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This adds the option --tpc-distortion-file to the TPC digitizer, so that the scaled distortions of a job are computed only once. - The first digitizer computes the scaled distortions and writes them to the file. - The other lanes and later timeframes read the file instead of recomputing. - The file is keyed on the ETags of the CCDB maps, TPCCorrMap.lumiInst and the mean-luminosity overrides. - A file written for other inputs is replaced. - A lock file serialises the digitizers of different processes. - Without a usable lock or ETag the distortions are computed as before. https://its.cern.ch/jira/browse/O2-7309 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This branch has not been deployed
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This PR adds the option
--tpc-distortion-fileto the TPC digitizer, so that the distortions scaled to the instantaneous luminosity are computed only once per job.With distortion type 2, every digitizer lane recalculates the scaled distortions from the CCDB maps in every timeframe. In Pb-Pb this takes about 3 minutes of CPU per lane and timeframe and, together with the correction maps it needs, more than 1 GB of memory per lane.
With the option, the first digitizer computes the scaled distortions and writes them to the file; the other lanes and the later timeframes of the job read it in under a second. The file is keyed on the ETags of the two CCDB maps,
TPCCorrMap.lumiInstand the mean-luminosity overrides, and a lock file makes sure that only one process computes. In addition, the correction maps are now released after the recalculation, since only the distortions are used for the digitization.The effect for one Pb-Pb timeframe (run 572106) with 8 lanes:
Note that the digits do not change: with and without the file they are identical to those of the current digitizer, and without the option the only change is the released correction maps. The use in O2DPG is prepared in AliceO2Group/O2DPG#2541, and the multithreaded digitizer of #16090 will use the same file once both are merged.
https://its.cern.ch/jira/browse/O2-7309
Assisted by Claude Code.