Messages in this thread | | | Date | Fri, 28 Feb 2014 14:47:41 -0800 | From | Greg KH <> | Subject | Re: [PATCH] intel_pstate: Change busy calculation to use fixed point math. |
| |
On Tue, Feb 25, 2014 at 10:35:37AM -0800, dirk.brandewie@gmail.com wrote: > From: Dirk Brandewie <dirk.j.brandewie@intel.com> > > Commit fcb6a15c2e Take core C0 time into account for core busy calculation. > > Introduced a regression on some processor SKUs supported by > intel_pstate. This was caused by the truncation caused by using > integer math to calculate core busy and C0 percentages. > > On a i7-4770K processor operating at 800Mhz going to 100% utilization > the percent busy of the CPU using integer math is 22% it actually is > 22.85%. This value scaled to the current frequency returned 97 which > the PID interpreted as no error and did not adjust the P state. > > Tested on i7-4770K, i7-2600, i5-3230M > > References: > https://lkml.org/lkml/2014/2/19/626 > https://bugzilla.kernel.org/show_bug.cgi?id=70941 > > Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Thanks, this fixed the issue for me:
Tested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| |