[arch-general] Default value of "j" in makeflags of makepkg.conf

[Joerg Schilling]

Isaac Dupree <ml at isaac.cedarswampstudios.org> wrote:

> Probably most code doesn't consume 256 MB RAM per GCC invocation.  C++'s 
> templates and lack of module system...

Correct...also in special for C and other compilers.

Important is to create more parallel instances then the number of available 
cores in order to have threads waiting for CPU while others are waiting for 
I/O. 

A rule of thumb is to invoke aprox. twice as many parallel build processes as 
the system has cores. This however is a rule derived on Solaris. On Linux, the 
scheduler may be worse and could impose a lower number.

Also note that when doing parallel builds with gmake, the problem is that 
unlike dmake (as used on Solaris), gmake does not serialize the output.
This causes problems when a build error has to be debugged.

Jörg

-- 
 EMail:joerg at schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
       js at cs.tu-berlin.de                (uni)  
       joerg.schilling at fokus.fraunhofer.de (work) Blog: http://schily.blogspot.com/
 URL:  http://cdrecord.berlios.de/private/ ftp://ftp.berlios.de/pub/schily