[CMake] Status/use of CMake on Cygwin

[Alan W. Irwin]

On 2013-05-20 11:52-0500 Kenneth Boyd wrote:

>> Can somebody with access to MSYS bash.exe on Microsoft Windows verify
>> that startup latency by timing "--version" options for standard
>> commands such as cmake?  If such times on a normal PC are hundreds of
>> milliseconds than you have confirmed the issue, but if they are only a
>> few milliseconds (8 on Linux, for example, for my entry level PC
>> hardware), then you have shown the issue doesn't exist for Microsoft
>> Windows which would contradict the above inefficient fork explanation.

> sh-3.1$ time gcc --version
> gcc.exe (4.3.3-tdm-1-dw2 mingw32) 4.3.3-dw2
> Copyright (C) 2008 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
>
>
> real    0m0.028s
> user    0m0.000s
> sys     0m0.015s
>
> Kenneth

Here are the corresponding (second-time) numbers here for Linux
and Wine.

software at raven> time gcc --version
gcc (Debian 4.7.2-5) 4.7.2
Copyright (C) 2012 Free Software Foundation, Inc.
[...]

real    0m0.002s
user    0m0.000s
sys     0m0.000s

That 0.002 seconds is so small that is probably only reliable
within a factor of two or so but indicates gcc --version
has hardly any overhead at all on Linux.

bash.exe-3.1$ time gcc --version
gcc.exe (GCC) 4.7.0
Copyright (C) 2012 Free Software Foundation, Inc.
[...]

real    0m0.176s
user    0m0.000s
sys     0m0.040s

That is an ugly factor of 90 or so compared to the Linux result.  Your
own value is 14 times my Linux value but 1 sixth my MSYS/Wine value so
it is hard to interpret it.  Do you have an equivalent result on your
hardware for Linux?

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
__________________________

Linux-powered Science
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