Date: Wed, 13 Feb 2008 09:08:42 -0500 From: Bill Moran <wmoran@potentialtech.com> To: Ed Schouten <ed@fxq.nl> Cc: Ian FREISLICH <ianf@clue.co.za>, current@freebsd.org Subject: Re: Testing box available. Message-ID: <20080213090842.65b240e6.wmoran@potentialtech.com> In-Reply-To: <20080213073155.GA1340@hoeg.nl> References: <E1JPBzl-0000jo-Pp@clue.co.za> <20080213073155.GA1340@hoeg.nl>
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In response to Ed Schouten <ed@fxq.nl>: > * Ian FREISLICH <ianf@clue.co.za> wrote: > > As an aside, a 64 way parallel make buildworld doesn't saturate the CPU. > > I'm not sure, but I think if you do this: > > make -j64 <foo> > > it only spawns 64 processes to handle the top level make process. This > would mean we've got a couple of processes doing this: > > make -C bin > make -C lib > make -C sbin > make -C usr.bin > make -C usr.sbin > > and the other processes will just quit, because they don't have anything > to do. Right? :-) Basically, -j tells make the _maximum_ number of jobs to run in parallel. I frequently do -j99, but I've never seen more than about 20. You can't just look at it for a second, either. Certain parts of the build process have more parallelism available than others, so you might look at it at a point where there are only a few. If you really want to saturate it, copy the src tree a few times and start a make -j99 buildworld in all of them simultaneously :D -- Bill Moran http://www.potentialtech.com
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