gijzelaerr
commented
10 years ago Original comment thread migrated from bugzilla
at 2011-06-30 16:08:00 Oleg Smirnov replied:
Ubuntu 10.04 and up ships a retarded, slow, badly compiled blitz, which reduces performance by a factor of several (due to thread locks being enabled even for element-level accesses). This can literally bring MeqTrees to its knees.
The only workaround I can see is shipping our own version of blitz, built without the threads stuff.
at 2011-07-14 14:27:41 Chris Williams replied:
Do you have a specific version in mind, and what options do you wish to be applied to get it built (I assume you are doing this already on your box)?
at 2011-07-14 14:35:17 Oleg Smirnov replied:
Yep, the build is documented on this wiki page:
http://www.astron.nl/meqwiki/BuildingTimba/RequiredSoftware/BlitzBuildNotes
Note also the small change required to build with newer g++s, also documented on that page.
The version is the "latest", i.e. 0.9. In fact, I suspect development of blitz
has ceased, since it's been stuck on 0.9 for donkey's years. Do you think we
should we just fork off 0.9, apply the #include
at 2011-07-14 14:54:46 Chris Williams replied:
Still seems to be some activity in CVS, they just don't seem to be making releases anymore. I already have patches to build it though, the problem is where to put it. Replacing the underlying distro's version is not a good idea - maybe some package somewhere relies on this thread locking stuff, so should go in /opt
at 2011-07-14 14:58:43 Oleg Smirnov replied:
Can we give it a different name? libblitz-meqtrees?
at 2011-08-29 23:43:04 Oleg Smirnov replied:
OK, we need to sort out one final wrinkle here. With the new blitz-mpp package installed (and the standard Ubuntu one wiped out), I struggled to build Timba because cmake could not find blitz. I finally persuaded it by passing - DBLITZ_INCLUDE_DIR=/opt/mpp/blitz/0.9/include/ and - DBLITZ_LIBRARY_DIR=/opt/mpp/blitz/0.9/lib/ to bootstrap_cmake, but this was by no means easy to figure out since our current cmake scripts do not give any feedback if the manual setting of BLITZ_INCLUDE_DIR and BLITZ_LIBRARY_DIR is incorrect.
Since our recommended path for building MeqTrees from source is to install the oxford dependency packages first, this error is going to hurt our advanced users. Could you please:
- update FindBlitz.cmake to look in /opt/mpp by default
- optionally: would be nice if the cmake step failed in an orderly manner if blitz/blitz.h and libblitz.a was not found at the manually-specified location. As things stand now, it's the actual build that fails, with a gazillion confusing messages.
at 2011-08-30 12:39:13 Chris Williams replied:
I've added the mpp packages default location in the Blitz search path (8376).
This is actually documented in the README_build.txt. I've added an example to help drive the point home to the uninitiated.
at 2011-06-30 16:08:00 Oleg Smirnov reported:
need to ship our own blitz on Ubuntu 10.04+