* Re: How to increase maximum user cpu usage allowed on a multi core system? [not found] <20150309120339.68ea8374@vfemail.net> @ 2015-03-17 18:34 ` poma 2015-03-17 18:50 ` Borislav Petkov 0 siblings, 1 reply; 2+ messages in thread From: poma @ 2015-03-17 18:34 UTC (permalink / raw) To: Borislav Petkov Cc: Community support for Fedora users, stan, Linux Kernel list On 09.03.2015 20:03, stan wrote: > I'm running Fedora 21 with a custom compiled kernel, > 3.19.0-1.20150211.fc21.x86_64. > > I have a multi core system with 6 cores. All are recognized by the > kernel. > > 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. > > On large compilations, like the kernel or firefox, even using 4 cores > could drastically reduce compile time. > > I've looked at /etc/security/limits.conf, but it doesn't seem to have a > setting for this. I've also looked at the /proc system to see if there > is a kernel variable, though that seems unlikely, with no luck. Online > searching found ways to limit the amount that a single job can get, but > not how to set this for a user. There must be a configuration variable > somewhere that is limiting the amount of total cpu a user can use. But > I can't find it. > > Can anyone help? > Borislav, can you help explain the man why this is happening with his Piledriver. http://www.cpu-world.com/CPUs/Bulldozer/AMD-FX-Series%20FX-6300.html poma ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: How to increase maximum user cpu usage allowed on a multi core system? 2015-03-17 18:34 ` How to increase maximum user cpu usage allowed on a multi core system? poma @ 2015-03-17 18:50 ` Borislav Petkov 0 siblings, 0 replies; 2+ messages in thread From: Borislav Petkov @ 2015-03-17 18:50 UTC (permalink / raw) To: poma; +Cc: Community support for Fedora users, stan, Linux Kernel list On Tue, Mar 17, 2015 at 07:34:08PM +0100, poma wrote: > On 09.03.2015 20:03, stan wrote: > > I'm running Fedora 21 with a custom compiled kernel, > > 3.19.0-1.20150211.fc21.x86_64. > > > > I have a multi core system with 6 cores. All are recognized by the > > kernel. > > > > 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. Let me try to understand this correctly? You're building the kernel with make -j6 but in htop you're seeing a single core at 100% and the rest are idle? Yes, no? What exact steps are you doing to build the kernel? Type them here please so that I can do them exactly on my system too. Also, please send a full dmesg from your system, private message is fine too. Thanks. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- ^ permalink raw reply [flat|nested] 2+ messages in thread
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2015-03-17 18:34 ` How to increase maximum user cpu usage allowed on a multi core system? poma
2015-03-17 18:50 ` Borislav Petkov
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