GC statistics

[Alex Rønne Petersen]

On 12-10-2012 05:38, dsimcha wrote:
> On Wednesday, 10 October 2012 at 19:35:33 UTC, Andrei Alexandrescu wrote:
>> This is mostly for GC experts out there - what statistics are needed
>> and useful, yet not too expensive to collect?
>>
>> https://github.com/D-Programming-Language/druntime/pull/236
>>
>>
>> Andrei
>
> I'd like to see mark, sweep and page-freeing time be counted separately
> so that if overall GC performance is slow, the user can identify where
> the bottleneck is.  For example, mark time will be slow if there's a lot
> of total memory to be scanned. Sweep time will be slow if there are a
> lot of blocks allocated, even if they're all small.  I'm not sure if
> this is feasible, though, because it assumes that the GC implementation
> is mark-sweep.  I guess we could name the subcategories something more
> generic like mark and process marks.

How do we best represent this in the statistics struct though? Wipe and 
set on every GC cycle or maintain some sort of average over time?

-- 
Alex Rønne Petersen
alex at lycus.org
http://lycus.org