On Wed, 15 Sep 2010 15:53:38 -0400, Rounin <[email protected]>
wrote:
I found this posting after investigating a huge slowdown in a D program
I'd made
using gprof, which showed the culprit to be a function called
_D3gcx3Gcx4markMFPvPvZv, in which the program spent 87% of its time.
That turned
out to be the garbage collector.
The program takes 1.74 seconds to run with two particular input files in
Python.
The garbage collected D version takes 5.27 seconds.
The non-garbage collected version takes only 0.68 seconds.
Here's a more detailed report:
http://rounin.livejournal.com/21815.html
Obviously, the compiled program should run at least as fast as Python,
so the
garbage collector could use some improvement.
gdc is very old. You may want to try the thing on the latest dmd. No
guarantee this is going to help though.
Another thing you may want to try is dcollections HashMap instead of
builtin associative arrays, as they use a free-list style allocator that
helps avoid GC collections.
I agree the GC is a major issue with performance, I hope after D2 is a bit
more stable, we start working on improving it.
-Steve
