https://github.com/torvalds/linux
Revision c717d1561493c58d030405c7e30e35459db31912 authored by Linus Torvalds on 04 June 2014, 14:48:54 UTC, committed by Linus Torvalds on 04 June 2014, 14:48:54 UTC
Pull intel pstate fixes from Rafael Wysocki:
 "Final power management fixes for 3.15

   - Taking non-idle time into account when calculating core busy time
     was a mistake and led to a performance regression.  Since the
     problem it was supposed to address is now taken care of in a
     different way, we don't need to do it any more, so drop the
     non-idle time tracking from intel_pstate.  Dirk Brandewie.

   - Changing to fixed point math throughout the busy calculation
     introduced rounding errors that adversely affect the accuracy of
     intel_pstate's computations.  Fix from Dirk Brandewie.

   - The PID controller algorithm used by intel_pstate assumes that the
     time interval between two adjacent samples will always be the same
     which is not the case for deferable timers (used by intel_pstate)
     when the system is idle.  This leads to inaccurate predictions and
     artificially increases convergence times for the minimum P-state.
     Fix from Dirk Brandewie.

   - intel_pstate carries out computations using 32-bit variables that
     may overflow for large enough values of APERF/MPERF.  Switch to
     using 64-bit variables for computations, from Doug Smythies"

* tag 'pm-3.15-final' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  intel_pstate: Improve initial busy calculation
  intel_pstate: add sample time scaling
  intel_pstate: Correct rounding in busy calculation
  intel_pstate: Remove C0 tracking
2 parent s 9e9a928 + bf81022
History
Tip revision: c717d1561493c58d030405c7e30e35459db31912 authored by Linus Torvalds on 04 June 2014, 14:48:54 UTC
Merge tag 'pm-3.15-final' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Tip revision: c717d15
File Mode Size
Documentation
arch
block
crypto
drivers
firmware
fs
include
init
ipc
kernel
lib
mm
net
samples
scripts
security
sound
tools
usr
virt
.gitignore -rw-r--r-- 1.1 KB
.mailmap -rw-r--r-- 4.4 KB
COPYING -rw-r--r-- 18.3 KB
CREDITS -rw-r--r-- 93.6 KB
Kbuild -rw-r--r-- 2.5 KB
Kconfig -rw-r--r-- 252 bytes
MAINTAINERS -rw-r--r-- 272.1 KB
Makefile -rw-r--r-- 50.5 KB
README -rw-r--r-- 18.3 KB
REPORTING-BUGS -rw-r--r-- 7.3 KB

README

back to top