On Thursday, 2 October 2014 at 20:31:29 UTC, Kiith-Sa wrote:
On Thursday, 2 October 2014 at 20:16:56 UTC, Gary Willoughby
wrote:
Say i have created a program written in D, what tools are
available for me to track memory allocations?
If you write a program and its performance is slow because you
suspect too many allocations are taking place in unrecognised
areas, what tools or techniques do you use to find where they
are and eliminate them?
If *time* spent by allocations is a problem, profile with `perf
top` (assuming you have Linux): Look for 'gc', 'malloc',
'calloc', etc.
(Plain perf record will also work, but not be as
quick/interactive. CodeXL works too.)
See https://perf.wiki.kernel.org/index.php/Tutorial - you
probably need some specific arguments to get caller info,
didn't use it for a while so I don't remember.
If e.g. the GC is an issue, it should be immediately evident
with some GC function taking e.g. over 5% of time. Usually the
actual overhead will be much higher but divided into multiple
smaller functions that will take little time individually.
Drill down into one of these and look at its callers. Eliminate
the most common source of calls, look again, repeat. Usually
removing a source of alloc calls will result in better speedup
than the profiler suggests.
If *space* is a problem, Valgrind doesn't work with most D
programs for some reason (probably D's fault), so, good luck
with that. But eliminating the biggest time wasters usually
helps space as well (or rather, it makes it more controllable
as you know better where you allocate memory).
Great thanks, I'll look into those.
