Revision 64897b20eed29cee2b998fb5ba362e65523dba3c authored by Rafael J. Wysocki on 21 March 2017, 21:19:07 UTC, committed by Rafael J. Wysocki on 21 March 2017, 21:19:07 UTC
The policy->cpuinfo.max_freq and policy->max updates in
intel_cpufreq_turbo_update() are excessive as they are done for no
good reason and may lead to problems in principle, so they should be
dropped.  However, after dropping them intel_cpufreq_turbo_update()
becomes almost entirely pointless, because the check made by it is
made again down the road in intel_pstate_prepare_request().  The
only thing in it that still needs to be done is the call to
update_turbo_state(), so drop intel_cpufreq_turbo_update() altogether
and make its callers invoke update_turbo_state() directly instead of
it.

In addition to that, fix intel_cpufreq_verify_policy() so that it
checks global.no_turbo in addition to global.turbo_disabled when
updating policy->cpuinfo.max_freq to make it consistent with
intel_pstate_verify_policy().

Fixes: 001c76f05b01 (cpufreq: intel_pstate: Generic governors support)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
1 parent 7de3255
Raw File
Kconfig.hz
#
# Timer Interrupt Frequency Configuration
#

choice
	prompt "Timer frequency"
	default HZ_250
	help
	 Allows the configuration of the timer frequency. It is customary
	 to have the timer interrupt run at 1000 Hz but 100 Hz may be more
	 beneficial for servers and NUMA systems that do not need to have
	 a fast response for user interaction and that may experience bus
	 contention and cacheline bounces as a result of timer interrupts.
	 Note that the timer interrupt occurs on each processor in an SMP
	 environment leading to NR_CPUS * HZ number of timer interrupts
	 per second.


	config HZ_100
		bool "100 HZ"
	help
	  100 Hz is a typical choice for servers, SMP and NUMA systems
	  with lots of processors that may show reduced performance if
	  too many timer interrupts are occurring.

	config HZ_250
		bool "250 HZ"
	help
	 250 Hz is a good compromise choice allowing server performance
	 while also showing good interactive responsiveness even
	 on SMP and NUMA systems. If you are going to be using NTSC video
	 or multimedia, selected 300Hz instead.

	config HZ_300
		bool "300 HZ"
	help
	 300 Hz is a good compromise choice allowing server performance
	 while also showing good interactive responsiveness even
	 on SMP and NUMA systems and exactly dividing by both PAL and
	 NTSC frame rates for video and multimedia work.

	config HZ_1000
		bool "1000 HZ"
	help
	 1000 Hz is the preferred choice for desktop systems and other
	 systems requiring fast interactive responses to events.

endchoice

config HZ
	int
	default 100 if HZ_100
	default 250 if HZ_250
	default 300 if HZ_300
	default 1000 if HZ_1000

config SCHED_HRTICK
	def_bool HIGH_RES_TIMERS
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