On 19.11.2014 09:21, Andy Lutomirski wrote: > On Mon, Nov 17, 2014 at 1:51 AM, Michel Dänzer <michel at daenzer.net> wrote: >> On 15.11.2014 07:21, Andy Lutomirski wrote: >>> >>> On recent kernels (3.16 through 3.18-rc4, perhaps), doing anything >>> graphics intensive seems to cause my system to become unusable for >>> tens of seconds. Pointing Firefox at Google Maps is a big offender -- >>> it can take several minutes for me to move my mouse far enough to >>> close the tab and get my computer back. >>> >>> On bootup, I get this warning: >>> [drm:btc_dpm_set_power_state] *ERROR* >>> rv770_restrict_performance_levels_before_switch failed >>> >>> Setting radeon.dpm=0 seems to work around this problem at the cost of >>> giving my rather slow graphics. >>> >>> Are there known issues here? >> >> >> Can you bisect the kernel, or at least isolate which kernel version first >> introduced the problem? > > With whatever userspace I'm running, I'm seeing it 3.13, 3.14, 3.15, > 3.16, and 3.18-rc4+. I haven't tried other versions. > > With radeon.dpm=0, I can still trigger short stalls (around one > second), but I seem unable to trigger long stalls easily. (I say > easily because, just as I was typing this email, my system stalled for > about a minute.)
I can only think of two things offhand that could cause such extremely long stalls: Swap thrashing or IRQ storms. With a setup where you can easily trigger long stalls, can you try getting a CPU profile for a stall with sysprof or perf? -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer
