Multithread Make in multicore server

[Rui Paulo]

On 4 Oct 2010, at 18:46, Kevin Mai wrote:

> I'm trying to do a "make buildworld" to build some jails on a Dell R710 server. 
> 
> It has 16 cores: 
> 
> [root at mrefns09 ~]# sysctl hw.ncpu 
> hw.ncpu: 16 
> 
> but, when doing running the "make buildworld" command: 
> 
> last pid: 77993; load averages: 1.07, 1.03, 0.95 up 38+01:12:10 17:42:09 
> 87 processes: 2 running, 85 sleeping 
> CPU 0: 1.9% user, 0.0% nice, 2.6% system, 0.0% interrupt, 95.5% idle 
> CPU 1: 0.0% user, 0.0% nice, 0.4% system, 0.0% interrupt, 99.6% idle 
> CPU 2: 1.9% user, 0.0% nice, 2.3% system, 0.0% interrupt, 95.9% idle 
> CPU 3: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle 
> CPU 4: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle 
> CPU 5: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle 
> CPU 6: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle 
> CPU 7: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle 
> CPU 8: 90.6% user, 0.0% nice, 5.6% system, 0.0% interrupt, 3.8% idle 
> CPU 9: 0.4% user, 0.0% nice, 0.4% system, 0.0% interrupt, 99.3% idle 
> CPU 10: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle 
> CPU 11: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle 
> CPU 12: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle 
> CPU 13: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle 
> CPU 14: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle 
> CPU 15: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle 
> Mem: 159M Active, 6514M Inact, 782M Wired, 126M Cache, 827M Buf, 324M Free 
> Swap: 8192M Total, 44K Used, 8192M Free 
> 
> I see that there's no multithreading when running make.. is there a way to enable multiprocessing when running make? 

Try 'make -j16 buildworld'. 16 is the maximum number of parallels processes that make is going to run.

Regards,
--
Rui Paulo