# Custom Kernels/Optimized OS/make.conf .. detail questions..



## linuxhelp (Mar 15, 2013)

Hi@ALL

FreeBSD 9.1-AMD64:

*I*'ve tried to recompile some custom kernels to reduce unwanted parts
- Where do users find useful make.conf settings
- Must the cputype be set? *I* didn't find setting Phenom X6 on Internet "hammer"?
- How to speed up the recompile of the whole system? 

*D*ump of make.conf:


```
WITHOUT_X11=yes
MAKEOPTS=-j7   # use 6 cores
BATCH=yes      # run batch
PERL_VERSION=5.12.4
MODULES_OVERRIDE=acpi  # shrink kernel
BUILD_OPTIMIZED=YES 
OPTIMIZED_CFLAGS=YES
CFLAGS=-O2 -pipe -fno-strict-aliasing # must this be set?
WITH_CPUFLAGS=YES #??
WITH_OPTIMIZED_CFLAGS=YES #??
WITHOUT_DEBUG=YES
BUILD_STATIC=YES #??
WITH_PKGNG=yes #pkgng use
```

*T*hanks.


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## fonz (Mar 15, 2013)

linuxhelp said:
			
		

> Where do users find useful make.conf settings[red]?[/red]


These forums and the make.conf(5) manpage come to mind.



			
				linuxhelp said:
			
		

> Must the cputype[red]CPU type[/red] be set? i[red]I[/red] didn't find [red]a[/red] setting Phenom X6 on Internet "hammer"??


If there is no specific value for your CPU, it can be set to a generic value, e.g. I686_CPU or something.



			
				linuxhelp said:
			
		

> Howto[red]How to[/red] speed up recompile[red]recompilation of[/red] the whole system?


You can use MODULES_OVERRIDE to have only the modules you really need built. And there should be a parallelisation flag somewhere too, although I wouldn't know off the top of my head what it is. Also, switching to single user mode might help in some cases.


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## kpa (Mar 15, 2013)

devel/ccache is about the only way to get real speed ups in my opinion.


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## wblock@ (Mar 15, 2013)

make.conf:


```
MAKEOPTS=-j7   # use 6 cores
```

I don't do that, it could interfere with the ports MAKE_JOBS setting.  When building world and kernel, I use -j8 on the command line.  Eight jobs was the fastest on both Core2 and i5 processors in my benchmarks.


```
BATCH=yes      # run batch
```

That takes away one of the best benefits of building from ports, the ability to set options.


```
MODULES_OVERRIDE=acpi  # shrink kernel
```

That will save a little space on disk, but does not really make the kernel smaller.


```
BUILD_OPTIMIZED=YES 
OPTIMIZED_CFLAGS=YES
CFLAGS=-O2 -pipe -fno-strict-aliasing # must this be set?
WITH_CPUFLAGS=YES #??
WITH_OPTIMIZED_CFLAGS=YES #??
```

No, don't do that.  That does not improve performance, but it does reduce compatibility, and it does slow down ports that can actually benefit from custom CFLAGS they set themselves.


```
WITHOUT_DEBUG=YES
BUILD_STATIC=YES #??
```

The first, meh.  The second... why?


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