The number of entries in the new test.root file is different from that in the original 3.root file. This only happens in the version 6.18.00 (not in 6.16.00) when the Implicit MT is turned on, and not for all the files. Actually this file dependence seems to be different between my linux desktop and mac laptop.
I’m sorry that I can’t provide a reproducer here. That file is still in use and I’m not sure if I can make it public.
The reproducer is pretty much what’s in the original post. But could you please try both of the files separately? It might be machine/platform dependent. And please let me know if you can’t reproduce the problem.
I didn’t try this on lxplus before. I just did it and as you said, it can’t be reproduced on lxplus.
However, I ran root with time and I noticed that the (user + sys) / real time ratio is about 15% (<100%) even with IMT on. Locally on my desktop, it’s >100%. I don’t know if this is because of the hard drive or eos performance. But I suspect this ratio matters if it’s a data race problem.
Although this can be a little annoying, may I suggest you run it locally (preferably on a machine with SSD)? Thank you!
It wasn’t clear from my message, but the test on ROOT master was performed on my workstation, using 8 cores and reading from SSD. There shouldn’t be any major differences in behavior between v6.18 and master, bit it would be great if you could check that you also see this behavior with ROOT master.
Indeed on lxplus most of the time is spent waiting for EOS.
The fix was merged into v6.18-00-patches and master.
You can test it by building ROOT or, from tomorrow, using the nightly builds of ROOT available on cvmfs, e.g. source /cvmfs/sft.cern.ch/lcg/views/dev3/Fri/x86_64-centos7-gcc8-opt/setup.sh (from tomorrow, the current Friday nightly is the one from last week).
You can also try right now on Linux with the prefix stack I use to test ROOT (not an official service). It has ROOT built nightly and deployed to CVMFS. Works on any Linux distribution with kernel 2.6.32 and above:
Entering Gentoo Prefix /cvmfs/sft.cern.ch/lcg/contrib/gentoo/linux/x86_64
$ root --version
ROOT Version: 6.19/01
Built for linuxx8664gcc on Jul 11 2019, 00:01:00