[Solved] How to put make -j2

[tele]

How to put make -j2 in

#%{?_smp_mflags} - corresponds to an option -j -build multiprocessor
%make %{?_smp_mflags}

[TerryN]

The _smp_mflags macro will expand to -j2 on a dual processor system.

So if you put:

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make %{?_smp_mflags}
in the %build section of the SPEC file it will expand to make -j2 on a dual processor system

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[terry@dell ~]$ rpm -E "make %{?_smp_mflags}"
make -j2

Also the %make macro already includes reference to _smp_mflags so just putting %make in the SPEC file will include the -j option on multiprocessor systems.

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[terry@dell ~]$ rpm -E "%make"
make -j2
Terry.

[tele]

macro will expand to -j2 on a dual processor system.

Not for Kadu software
in Kadu this is work  make -jx + number cores , where x=1 and  one core = 1, two cores=2 , tree cores =3 , etc.
so  1+1= 2 ,
so  make -j2 and this is for  only one  processor system - this is from manual Kadu
I don't know why this is work , I do not know if this is correct.

But thanks, now I know for what %{?_smp_mflags} this is and how to put.

[TerryN]

I don't know why this is work , I do not know if this is correct.

The -j option to make specifies the number of jobs to run simultaneously during the build.  You can set it to anything you like.  The only effect it has is on how long the build will take.  It makes sense to set it to at least the number of processors and that is what the RPM macros do.  It is debatable whether setting it higher makes any significant improvement to build speed.   Since our SRPMS need to build efficiently on any packager's machine it is better to stick with the RPM defaults.

Terry.