On Wednesday, November 22, 2017 8:48:08 AM CET David Haller wrote: > Hello, > > On Wed, 22 Nov 2017, Raffaele Belardi wrote: > >rebuilding system and world with gcc-7.2.0 on a 6-core AMD CPU I have > >the impression that most of the ebuilds limit parallel builds to 1, 2 > >or 3 threads. > > Most should build with "many" cores, but some might be limited, but ... > > >I'm aware it is only an impression, I did not spend the > >night monitoring the process, but nevertheless every time I checked > >the load was very low. > > I guess you're mostly observing stalls because the (single-thread) > overhead of emerge, configure (etc.), which can also be IO-bound... > The actual builds probably goes so fast on your box, you hardly > notice unless they're rather big(gish). > > Some numbers for comparison, and I generally build with just one > thread in the background on my 2 core "old" Athlon II X2 250: > dev-libs/boost took a good 45mins to build with one thread. Divide by > 6 for your cores, divide again by about 2-3 for your newer cores and > you're in the 3:45min range for such a "biggie" as boost. Most other > stuff won't even peg your meter. > > So, your emerge is mostly IO and "emerge"-threads bound. Solution: > adjust your build-threads[1], and then adjust your emerge jobs! See > '--jobs' in 'man emerge'. Can't find where to set a default in a > config-file for that ATM, but you could always alias/function/script > emerge to something else, e.g. put this in your ~/.bashrc:
Instead of all these aliases, simply edit your make.conf ( /etc/portage/ make.conf ) And edit (or add) the following lines: MAKEOPTS="--jobs 24 --load-average 48" EMERGE_DEFAULT_OPTS="--jobs 24 --load-average 48" Adjust the values to match your system, the above works fine on my desktop. CPU: Intel(R) Core(TM) i7-5820K CPU @ 3.30GHz And 32GB ram. -- Joost
