RFC: change default build to always be optimized (even for developers) #1417
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Why not a different, less annoying approach? The comments in the code explicitly state that defaulting to a debug build when using a repo was done for "early development" purposes. So why not just turn that off? It would be much less annoying to have to remember to enable-debug. |
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Yeah, I just replied on the mailing list -- I think we agreed to do this last week in Dallas, anyway (disable debug-by-default builds). I think these could still be complimentary features though -- if debug builds are not common (because they're not the default), then perhaps a warning like this is less obtrusive, anyway. I'll add a "don't do a debug build by default" commit to this PR. |
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Ok, I added a 2nd commit that disables debug-build-by-default behavior if a .git directory is found. |
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I believe @gpaulsen was going to do it, but I see you've done it here. Pretty trivial change. I would advocate to remove the warning and just do your 2nd commit. |
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No worries. I made a comment on the commit. Is that easily visible to you Jeff? I assume it emailed you. |
jsquyres
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@gpaulsen The milestone on this PR is v2.1.0. Per discussion on the call today, it seems like everyone is comfortable with:
I.e., you only get a debug build if you ask for it, and if you asked for it, we don't need to give you a warning. PR has been updated. |
I'm very happy to see this change, I've found it to be surprising since basically forever. |
jsquyres
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Point made 15 Mar 2016 webex: it would be nice to leave Ok, will do. |
After 11 years, it's probably ok to say that we're no longer in "early development" -- disable the "build a debug version of Open MPI by default if we find a .git directory" behavior. However, we are keeping the "use compiler picky flags if we find a .git directory" behavior. That's useful behavior for developers, and has no effect on performance.
Make the help messages for --enable-mem-debug and --enable-mem-profile the same as other help messages.
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PR updated per the above comment. |
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bot:retest |
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@miked-mellanox Is the Mellanox Jenkins busted at the moment? |
RFC: change default build to always be optimized (even for developers)
A not-uncommon complaint we hear is someone who gets lower-than-expected performance, and it is later discovered that they used a debugging build. This commit enables ortertun to automatically print a stern warning/admonishion to not use this build for performance tests if it is a debug build. You can use the
orterun --nowarn-debug-buildCLI option to disable this message, or exportOMPI_MCA_nowarn_debug_build=1.The rationale for this option is to make it totally, completely obvious that you are using a debug build. Yes, this extra output will screw up the output of running benchmarks and other applications. That's kinda the point -- if you're running benchmarks / parsing stdout to get performance data, you shouldn't be using a debugging build, and we want to smack you in the face with that fact.
That being said, there are many useful scenarios for a debug build. Hence, you can disable the warning with an mpirun CLI option and/or setting an env var.
Comments?