[Interest] porting to Qt 5.4 - MOC very slow on Windows

Thiago Macieira thiago.macieira at intel.com
Thu Jan 15 18:48:16 CET 2015

On Thursday 15 January 2015 14:16:37 Keith Gardner wrote:
> Do you have the /MP flag set for your project?  Even though MOC takes
> longer, this will at least allow you to run one instance of MOC for every
> core on your system in addition to reducing build times in general.

The /MP flag is a compiler flag, telling the compiler to be multithreaded. 
cl.exe doesn't compile in each of the instances of the compiler; instead, it 
finds running instance and tells it to compile the source that it was given. 
That's how cl.exe implements /MP.

After a while, that compiling instance exits. Moreover, that doesn't apply to 
other processes.

If you want to make full use of your CPU cores, use jom.exe, not nmake.exe.
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center

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