Luca's meaningless thoughts  


by Leandro Lucarella on 2009- 08- 18 00:26 (updated on 2009- 08- 18 00:26)
tagged benchmark, collection, d, dgc, dgcbench, en, gc, graph, naive, statistics - with 0 comment(s)

It's been exactly 3 months since the last post. I spent the last months writing my thesis document (in Spanish), working, and being unproductive because of the lack of inspiration =)

But in the last couple of days I decided to go back to the code, and finish the statistics gathering in the Naive GC (the new code is not published yet because it needs some polishing). Here are some nice graphs from my little D GC benchmark:

big_arrays rnd_data rnd_data_2 shootout_binarytrees split startup tree

The graphs shows the space and time costs for each collection in the programs life. The collection time is divided in the time spent in the malloc() that triggered the collection, the time spent in the collection itself, and the time the world has to be stopped (meaning the time all the threads were paused because of the collection). The space is measured before and after the collection, and the total memory consumed by the program is divided in 4 areas: used space, free space, wasted space (space that the user can't use but it's not used by the collector either) and overhead (space used by the collector itself).

As you can see, the naive collector pretty much sucks, specially for periods of lots of allocation (since it just allocated what it's asked in the gc_malloc() call if the collection failed).

The next step is to modify the Tango's Basic collector to gather the same data and see how things are going with it.