Re: [Boost-build] [patch review] Re: Help optimizing a slow BJAM build

From: Jurko Gospodnetiæ (jurko.gospodnetic_at_[hidden])
Date: 2008-04-10 05:01:25

   Hi Igor.

> I'm attaching a synthetic test case that shows the slowdown. To run
> the test, unpack the Jamfile to an empty directory and run bjam in
> that directory.

   Ok, I tried your test case and maybe I am doing something wrong but 
my timings show no significant difference between base milestone 12, 
current trunk & patched current trunk versions.

   Here are the things I noticed:

   The test case was missing a Jamroot file - so maybe something in the 
Jamroot file you're using is triggering this behavior. Seems unlikely, 
but could you send a self-sufficient test case just to make sure?

   Directly running your test case (even after adding an empty Jamroot 
file) on my machine did nothing and exited instantly - most likely due 
to a memory allocation error (returned error code is -1073741819). To 
make it work I needed to remove the last 3709 entries. Could it be that 
your project is running into the same or similar kind of failure with 
the new code and is so silently not sorting the list at all?

   It is interesting that the milestone 12 build can handle a bit larger 
list entry, but still not the whole one.

   Just for the record - my notebook has 2 GB RAM and a few programs 
started on it :-)...

   Hope this helps.

   Best regards,
     Jurko Gospodnetiæ