On Tue, 10 Mar 2015 11:35:24 +0100 Heinz Diehl <htd+ml@xxxxxxxxxx> wrote: > On 09.03.2015, stan wrote: > > > But, when I run a compile job with -j6, in order to allow all six > > cores to be used, it limits the total amount of usage to 100% of a > > *single* core. So, it might use all six cores, but the sum of the > > percentages on those six cores is always around 100% of one core. > > This is from htop output. > > This is the CPU scheduler not maximizing usage. Try this next time: > > nice -n -20 make -j6 > > Or choose any nice level which fits better for you, "man nice". > Thanks. When I had a single core machine, I used to adjust ionice and nice to be ultra kind on heavy jobs so they wouldn't impact my graphical interface experience. Worked fine. I tried making the job more greedy as you suggest, and it refuses because I don't have the authority to adjust niceness down. I don't want to run it as root, and I shouldn't have to. I don't see why this is necessary. The system is showing 470% idle. So the kernel cpu scheduler shouldn't need to limit the job to a single core maximum usage. Even if it leaves some margin for error, it should still be using more than a single core equivalent. The kernel programmers are smart folks. Not to mention that they do large compilations on multi-core machines often. I doubt that they hard coded this kind of behavior into the kernel. So there must be a setting that is limiting the kernel scheduler in some way. Maybe it's the scheduler that is being used. I'm using 'on demand' rather than 'performance'. 'Performance' sounds like it keeps everything at full rev all the time. While power isn't an issue for me, I don't see a reason to generate all that heat. I'll keep plugging away, reading and experimenting, until I get it or give up. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
