Visual D Build + DMD Bugginess = Bad

[Nick Sabalausky]

"Denis Koroskin" <2korden at gmail.com> wrote in message 
news:op.vksxyn15o7cclz at korden-pc...
> On Tue, 19 Oct 2010 06:26:23 +0400, Nick Sabalausky <a at a.a> wrote:
>
>> "Denis Koroskin" <2korden at gmail.com> wrote in message
>>> Running the build script  takes 7.967 seconds for me (timed with timeit,
>>> part of the Windows Server  2003 Resource Kit Tools).
>>
>> My guess is it may be the multi-threaded "process multiple modules in
>> parallel" optimization. DDMD does have a *lot* of source files. And I'm 
>> on a
>> single-core (yea, yea, I know, but it works for me and I have no money).
>>
>> I'm curious, is it possible for you or Rainer to time it running dmd in a
>> "force single-core" mode? Ideally using the main system/OS core (if there
>> even is one)? I would expect a normal out-of-the-box dmd would be 
>> noticably
>> faster for you two just because of that multi-thread/core optimization 
>> and
>> the cores themselves just simply being faster, but 120 sec vs 8 sec still
>> seems an excessive difference.
>>
>> And then considering also, outside of dmd bugs, I've never once had any D
>> program besides ddmd take more than a few seconds - despite the fact that
>> much of what I do complie is fairly template/mixin/ctfe-heavy, and ddmd
>> appears to use very little (if any) of that - it's certainly still a
>> conceivable speed difference, but it does make me wonder if something 
>> else
>> might be going on.
>>
>> BTW, anyone know of an easy way to check how much time in a process is 
>> spent
>> waiting on disk IO? It's entirely possible that my disk is just 
>> fragmented
>> all to hell.
>>
>>
>
> dmd doesn't use multiple core for anything BUT asynchronous reading from 
> disk. Everything else is done is a single thread.

Ahh, I see. So much for that theory then.

> I don't think it has  THAT big of impact, but I'll try to recompile with 
> all the cores disabled.

Thanks, that'll be interesting.

I did go ahead and re-time the compile. Apparently I must have been 
remembering it wrong, because this time it only took 1 min 20 sec (and this 
was with a ton of stuff running - bunch of misc apps, FF2 with 20 tabs, an 
HDD SMART monitor, a torrent manager and a bunch of other servers (but no 
clients connected)). But that's still quite a lot of time to compile a D 
app, even for my machine.

I also tried grabbing the latest ddmd, rebooted, killed all non-essential 
processes, and tried that way. Got it down to just slightly under one 
minute.

I thought about maybe it being a limited-memory issue (remembering that dmd 
never frees anything until it's done - or is that just CTFE?), but I don't 
think that's it - the highest memory usage it ever got was about 200MB, and 
I have 1GB, and it still took a whole minute with almost everything besides 
XP shut down, so I'm not sure that was it. (I could have sworn I had 2GB at 
one point, but I think I probably cannibalized one of the sticks when I 
built my linux box - not that that's really relevant ;) )

FWIW, this is all with compiling the just the debug version of ddmd only. 
Ie, not including building the release version or the one-time initial setup 
of building dmd.lib.