D on quora ...

[Jon Degenhardt]

On Saturday, 7 October 2017 at 03:15:41 UTC, Laeeth Isharc wrote:
> On Saturday, 7 October 2017 at 01:00:41 UTC, Jon Degenhardt 
> wrote:
>> Have there been studies quantifying the performance of D's GC 
>> relative to other GC implementations? My anecdotal experience 
>> is that D's GC can have undesirable latency behavior (long 
>> pauses), but throughput appears good. Of course, quantified 
>> metrics would be far preferable to anecdotal observations.
>>
>> --Jon
>
> Have you tried running the GC instrumentation on your tsv 
> utilities? That might make for a very interesting blog post.

Well, I have for the tsv utilities and some other programs. 
That's what's behind my observations. While interesting, I don't 
think I have enough definitive data to draw conclusions for a 
blog post. Two specifics:
(1) GC profile data shows long max pause times in several 
benchmarks. However, where it has occurs it's clearly associated 
with very large AAs. It may not be representative of more common 
use cases. (There is more quantification I could do here though.)
(2) The benchmarks I've run are all on throughput oriented tasks. 
In these the D programs have compared well to other native 
compiled programs, mostly using manual memory management. I think 
this does say something to the effect that choosing good 
algorithms and memory use approaches is usually more important 
than the GC vs manual memory selection. And, it is consistent 
with a good throughput story for D's GC, but is hardly a direct 
comparison.