On Sat, Nov 3, 2012 at 12:48 PM, Mike Galbraith <efault@xxxxxx> wrote: > On Sat, 2012-11-03 at 04:33 -0700, Mike Galbraith wrote: >> On Fri, 2012-11-02 at 21:09 +0100, Michal Zatloukal wrote: >> >> > On the new kernel, the nice processes are never starved - even when >> > starting a tab-laden chromium session, the processes for BOINC keep >> > about 20% CPU each (that is normalized to all CPUs, ie 40% nice load >> > on each core). The problem is, the governor now seems to consider the >> > non-nice task unable to saturate the CPU, and the cores' frequencies >> > are hovering between 1.0 and 1.8 GHz. The scheduler keeps scheduling >> > the nice tasks, and the non-nice tasks are progressing much slower, >> > caused by the lower CPU speed as well as less processing time >> > allocated to them. HD video stutters often, and Chromium takes at >> > least 2-3 times longer to fully load. >> >> Your nice 19 tasks receiving 'too much' CPU when there are other >> runnable tasks around sounds like you have SCHED_AUTOGROUP enabled. > > (forgot to mention: if that's the case, you can add noautogroup to your > kernel command line to turn it off if distro turned it on in .config) > Thanks, Ubuntu's kernel is indeed configured with that option enabled, and passing "noautogroup" at grub restores the previous behaviour. I'm back to happy days again :) BTW, isn't this the "magic 200-line patch" I was reading about ~2 years ago? MZ -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
