https://bugzilla.kernel.org/show_bug.cgi?id=70941 Bug ID: 70941 Summary: 'powersave' performance excessively slow on Dell Venue 8 Pro (Baytrail tablet) Product: Power Management Version: 2.5 Kernel Version: 3.14rc3 Hardware: i386 OS: Linux Tree: Fedora Status: NEW Severity: high Priority: P1 Component: cpufreq Assignee: cpufreq@xxxxxxxxxxxxxxx Reporter: awilliam@xxxxxxxxxx Regression: No I've noticed recent 3.14 kernels perform extremely sluggishly on my Venue 8 Pro (Baytrail-based tablet). Doing 'echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor' speeds things right up again: default is 'powersave'. Obviously performance will be faster, but powersave seems really egregiously slow. Just stuff like paging through console output at a VT is incredibly sluggish - I can run 'journalctl -b', hit End, and watch it draw one painful line at a time. The scaling_driver is 'intel_pstate' . I think pstate stuff may have been broken on baytrail for a while - I had to boot with intel_pstate=disable for a bit, and before that it may just not have been kicking in - which is probably why I didn't notice this until rc2 or so. The frequency range is 200MHz->1.6GHz with both 'powersave' and 'performance'. I'm not sure what's the best way to watch the scaling kick in, but using powertop or just spamming 'cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq' , it does seem to scale up rather faster with performance. Not sure what info is needed to help debug this, just ask and I'll provide. -- You are receiving this mail because: You are the assignee for the bug. -- 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
