Thread overview
Huge increase in UT compile time
Oct 11
Dhananjay
Oct 11
Dhananjay
Oct 14
Joakim
October 11
Hello,

I am upgrading to DMD 2.076.1 from DMD 2.069.2 (similar results on 2.075.1), and seeing a huge increase in unittest compilation time when the -deps parameter is also passed to dmd. This is on both OSX and linux. What can be the cause of this?

Sample program:

    import std.stdio: writeln;

    unittest { writeln("TestUT"); }

    version (unittest) {}
    else
    {
        void main()
        {
            writeln("TestMain");
        }
    }

Observations:

Command: time dmd -deps=test.dep -c -o- test.d -de -w -m64 -color -g -debug -gs -unittest -main
Linux runtime: user 0m28.192s    << Note the increase
OSX runtime: user 0m48.508s     <<
Linux 2.069.1 runtime: user 0m0.009s

Command: time dmd -c -o- test.d -de -w -m64 -color -g -debug -gs -unittest -main
Linux runtime: user 0m0.064s
OSX runtime: user 0m0.090s
Linux 2.069.1 runtime: user 0m0.005s

Command: time dmd -deps=test.dep -c -o- test.d -de -w -m64 -color -g -debug -gs
Linux runtime: user 0m0.584s
OSX runtime: user 0m0.882s
Linux 2.069.1 runtime: user 0m0.007s

Command: time dmd -c -o- test.d -de -w -m64 -color -g -debug -gs
Linux runtime: user 0m0.048s
OSX runtime: user 0m0.074s
Linux 2.069.1 runtime: user 0m0.010s

Environment:
OSX: El Capitan 10.11.6
Linux with DMD 2.076.1: Gentoo 4.9.34
Linux with DMD 2.069.1: Centos 7
October 11
Another observation:
wc -l test.dep (for "-deps=test.dep ... -unittest -main" command):
Linux 2.076.1: 41389
Linux 2.069.1: 144

Making small changes to 2.069.1 runtimes (I had run with a different program by mistake. The measurement is still of the same order)

On Wednesday, 11 October 2017 at 06:25:19 UTC, Dhananjay wrote:
> Hello,
>
> I am upgrading to DMD 2.076.1 from DMD 2.069.2 (similar results on 2.075.1), and seeing a huge increase in unittest compilation time when the -deps parameter is also passed to dmd. This is on both OSX and linux. What can be the cause of this?
>
> Sample program:
>
>     import std.stdio: writeln;
>
>     unittest { writeln("TestUT"); }
>
>     version (unittest) {}
>     else
>     {
>         void main()
>         {
>             writeln("TestMain");
>         }
>     }
>
> Observations:
>
> Command: time dmd -deps=test.dep -c -o- test.d -de -w -m64 -color -g -debug -gs -unittest -main
> Linux runtime: user 0m28.192s    << Note the increase
> OSX runtime: user 0m48.508s     <<
    Linux 2.069.1 runtime: user 0m0.045s <edited>
>
> Command: time dmd -c -o- test.d -de -w -m64 -color -g -debug -gs -unittest -main
> Linux runtime: user 0m0.064s
> OSX runtime: user 0m0.090s
   Linux 2.069.1 runtime: user 0m0.053s <edited>
>
> Command: time dmd -deps=test.dep -c -o- test.d -de -w -m64 -color -g -debug -gs
> Linux runtime: user 0m0.584s
> OSX runtime: user 0m0.882s
  Linux 2.069.1 runtime: user 0m0.035s  <edited>
>
> Command: time dmd -c -o- test.d -de -w -m64 -color -g -debug -gs
> Linux runtime: user 0m0.048s
> OSX runtime: user 0m0.074s
  Linux 2.069.1 runtime: user 0m0.036s   <edited>
>
> Environment:
> OSX: El Capitan 10.11.6
> Linux with DMD 2.076.1: Gentoo 4.9.34
> Linux with DMD 2.069.1: Centos 7


October 11
On Wednesday, October 11, 2017 06:25:19 Dhananjay via Digitalmars-d-learn wrote:
> Hello,
>
> I am upgrading to DMD 2.076.1 from DMD 2.069.2 (similar results on 2.075.1), and seeing a huge increase in unittest compilation time when the -deps parameter is also passed to dmd. This is on both OSX and linux. What can be the cause of this?

Well, that's a pretty big version jump. So, a lot could have changed. One thing that comes to mind would be that imports were overhauled pretty thoroughly to try and fix various import bugs. This blog article talks about some of that:

http://www.schveiguy.com/blog/2016/03/import-changes-in-d-2-071/

Or the change could be the result of something else entirely. Figuring it out would likely require doing a fair bit of debugging to narrow down when the change happened (and that's assuming that it's caused by a single commit or small set of commits rather than simply getting worse over time due to a variety of factors).

- Jonathan M Davis

October 14
On Wednesday, 11 October 2017 at 08:11:37 UTC, Jonathan M Davis wrote:
> On Wednesday, October 11, 2017 06:25:19 Dhananjay via Digitalmars-d-learn wrote:
>> Hello,
>>
>> I am upgrading to DMD 2.076.1 from DMD 2.069.2 (similar results on 2.075.1), and seeing a huge increase in unittest compilation time when the -deps parameter is also passed to dmd. This is on both OSX and linux. What can be the cause of this?
>
> Well, that's a pretty big version jump. So, a lot could have changed. One thing that comes to mind would be that imports were overhauled pretty thoroughly to try and fix various import bugs. This blog article talks about some of that:
>
> http://www.schveiguy.com/blog/2016/03/import-changes-in-d-2-071/
>
> Or the change could be the result of something else entirely. Figuring it out would likely require doing a fair bit of debugging to narrow down when the change happened (and that's assuming that it's caused by a single commit or small set of commits rather than simply getting worse over time due to a variety of factors).
>
> - Jonathan M Davis

The following observations (for the above test program) were recorded on Mac OS X 10.11.6:

DMD64 D Compiler v2.073.1
real    0m0.091s
user    0m0.067s
sys 0m0.020s

DMD64 D Compiler v2.074.0
real    0m0.105s
user    0m0.072s
sys 0m0.022s

DMD64 D Compiler v2.075.1
real    0m44.932s
user    0m35.732s
sys 0m7.098s

DMD64 D Compiler v2.076.1
real    0m46.833s
user    0m37.827s
sys 0m7.254s

Furthermore, 2.075.1 gave a bunch of deprecation warnings in std/string.d. The -de switch had to be removed before running.

Hope this helps,
Saurabh


October 14
On Saturday, 14 October 2017 at 04:36:25 UTC, Saurabh Das wrote:
> On Wednesday, 11 October 2017 at 08:11:37 UTC, Jonathan M Davis wrote:
>> On Wednesday, October 11, 2017 06:25:19 Dhananjay via Digitalmars-d-learn wrote:
>>> Hello,
>>>
>>> I am upgrading to DMD 2.076.1 from DMD 2.069.2 (similar results on 2.075.1), and seeing a huge increase in unittest compilation time when the -deps parameter is also passed to dmd. This is on both OSX and linux. What can be the cause of this?
>>
>> Well, that's a pretty big version jump. So, a lot could have changed. One thing that comes to mind would be that imports were overhauled pretty thoroughly to try and fix various import bugs. This blog article talks about some of that:
>>
>> http://www.schveiguy.com/blog/2016/03/import-changes-in-d-2-071/
>>
>> Or the change could be the result of something else entirely. Figuring it out would likely require doing a fair bit of debugging to narrow down when the change happened (and that's assuming that it's caused by a single commit or small set of commits rather than simply getting worse over time due to a variety of factors).
>>
>> - Jonathan M Davis
>
> The following observations (for the above test program) were recorded on Mac OS X 10.11.6:
>
> DMD64 D Compiler v2.073.1
> real    0m0.091s
> user    0m0.067s
> sys 0m0.020s
>
> DMD64 D Compiler v2.074.0
> real    0m0.105s
> user    0m0.072s
> sys 0m0.022s
>
> DMD64 D Compiler v2.075.1
> real    0m44.932s
> user    0m35.732s
> sys 0m7.098s
>
> DMD64 D Compiler v2.076.1
> real    0m46.833s
> user    0m37.827s
> sys 0m7.254s
>
> Furthermore, 2.075.1 gave a bunch of deprecation warnings in std/string.d. The -de switch had to be removed before running.
>
> Hope this helps,
> Saurabh

I can reproduce on linux/x64, looks like a memory leak, as dmd balloons out to eat up all available memory until it's killed.  I see it with this minimal command passed to dmd 2.075.1, but not the 2.074.1 frontend, as reported:

./dmd2/linux/bin64/dmd -c -o- foo.d -unittest -deps=foo.deps

The closest issue I was able to find in bugzilla is this one, but that says it goes away with -o-, not the case here:

https://issues.dlang.org/show_bug.cgi?id=17601

I suggest one of you file a bug with the minimal command, noting that it goes away if -unittest or -deps is not passed.  Make sure you mark it as a regression, just like the above bug, as Walter pays special attention to those.
October 14
On Saturday, 14 October 2017 at 09:03:05 UTC, Joakim wrote:
> On Saturday, 14 October 2017 at 04:36:25 UTC, Saurabh Das wrote:
>> [...]
>
> I can reproduce on linux/x64, looks like a memory leak, as dmd balloons out to eat up all available memory until it's killed.  I see it with this minimal command passed to dmd 2.075.1, but not the 2.074.1 frontend, as reported:
>
> ./dmd2/linux/bin64/dmd -c -o- foo.d -unittest -deps=foo.deps
>
> The closest issue I was able to find in bugzilla is this one, but that says it goes away with -o-, not the case here:
>
> https://issues.dlang.org/show_bug.cgi?id=17601
>
> I suggest one of you file a bug with the minimal command, noting that it goes away if -unittest or -deps is not passed.  Make sure you mark it as a regression, just like the above bug, as Walter pays special attention to those.

Filed a bug report: https://issues.dlang.org/show_bug.cgi?id=17898

Hope I didn't miss anything.