On Fri, Jan 7, 2011 at 7:54 PM, Ted Unangst <ted.unan...@gmail.com> wrote: > On Fri, Jan 7, 2011 at 1:18 PM, Christian Weisgerber <na...@mips.inka.de> > wrote: >> I guess Landry doesn't read this list, or he could tell you how his >> experiment with parallel ports building on a 64-way sparc64 T2 went. >> With 32 build jobs it looked like this: >> >> <landry_p22> 0.8%Int 48.9%Sys 6.0%Usr 0.0%Nic 44.3%Idle >> <landry_p22> around that all the time > > My understanding is that the T2 is closer to an 8-way machine. If we > could recognize the real cores and balance appropriately, 8 build jobs > shouldn't be too bad. > > At least with a 4-core 8-thread i7 processor, make -j 8 scales reasonably > well.
In that particular case, dpb jobs are a bit different than just running 'make -j'. It's more like "oh let's build XX ports at the same time", which is a perfect stresstest for smp. 32 Build jobs made the machine totally unusable (load was constant around 40/45 iirc), so far i've settled for 12 jobs, which spawns approx ~50/60 make processes in parallel (a single port build spawns 4/5 makes), more or less the same amount of shells, and smth like ~20 ssh process as it's the dpb master node. Load is constant around 20, and the machine is still 'responsive'. 227 processes: 210 idle, 17 on processor All CPUs: 5.8% user, 0.0% nice, 16.9% system, 0.8% interrupt, 76.5% idle Landry
