linux-toradex.git/drivers/cpufreq/Makefile, branch tegra

cpufreq: interactive: New 'interactive' governor

2011-12-01T05:38:25+00:00

This governor is designed for latency-sensitive workloads, such as
interactive user interfaces.  The interactive governor aims to be
significantly more responsive to ramp CPU quickly up when CPU-intensive
activity begins.

Existing governors sample CPU load at a particular rate, typically
every X ms.  This can lead to under-powering UI threads for the period of
time during which the user begins interacting with a previously-idle system
until the next sample period happens.

The 'interactive' governor uses a different approach. Instead of sampling
the CPU at a specified rate, the governor will check whether to scale the
CPU frequency up soon after coming out of idle.  When the CPU comes out of
idle, a timer is configured to fire within 1-2 ticks.  If the CPU is very
busy from exiting idle to when the timer fires then we assume the CPU is
underpowered and ramp to MAX speed.

If the CPU was not sufficiently busy to immediately ramp to MAX speed, then
the governor evaluates the CPU load since the last speed adjustment,
choosing the highest value between that longer-term load or the short-term
load since idle exit to determine the CPU speed to ramp to.

A realtime thread is used for scaling up, giving the remaining tasks the
CPU performance benefit, unlike existing governors which are more likely to
schedule rampup work to occur after your performance starved tasks have
completed.

The tuneables for this governor are:
/sys/devices/system/cpu/cpufreq/interactive/min_sample_time:
	The minimum amount of time to spend at the current frequency before
	ramping down. This is to ensure that the governor has seen enough
	historic CPU load data to determine the appropriate workload.
	Default is 80000 uS.
/sys/devices/system/cpu/cpufreq/interactive/go_maxspeed_load
	The CPU load at which to ramp to max speed.  Default is 85.

Change-Id: Ib2b362607c62f7c56d35f44a9ef3280f98c17585
Signed-off-by: Mike Chan 
Signed-off-by: Todd Poynor 
Bug: 3152864

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2011-07-26T05:59:39+00:00

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (99 commits)
  drivers/virt: add missing linux/interrupt.h to fsl_hypervisor.c
  powerpc/85xx: fix mpic configuration in CAMP mode
  powerpc: Copy back TIF flags on return from softirq stack
  powerpc/64: Make server perfmon only built on ppc64 server devices
  powerpc/pseries: Fix hvc_vio.c build due to recent changes
  powerpc: Exporting boot_cpuid_phys
  powerpc: Add CFAR to oops output
  hvc_console: Add kdb support
  powerpc/pseries: Fix hvterm_raw_get_chars to accept < 16 chars, fixing xmon
  powerpc/irq: Quieten irq mapping printks
  powerpc: Enable lockup and hung task detectors in pseries and ppc64 defeconfigs
  powerpc: Add mpt2sas driver to pseries and ppc64 defconfig
  powerpc: Disable IRQs off tracer in ppc64 defconfig
  powerpc: Sync pseries and ppc64 defconfigs
  powerpc/pseries/hvconsole: Fix dropped console output
  hvc_console: Improve tty/console put_chars handling
  powerpc/kdump: Fix timeout in crash_kexec_wait_realmode
  powerpc/mm: Fix output of total_ram.
  powerpc/cpufreq: Add cpufreq driver for Momentum Maple boards
  powerpc: Correct annotations of pmu registration functions
  ...

Fix up trivial Kconfig/Makefile conflicts in arch/powerpc, drivers, and
drivers/cpufreq

powerpc/cpufreq: Add cpufreq driver for Momentum Maple boards

2011-07-19T05:13:04+00:00

Add simple cpufreq driver for Maple-based boards (ppc970fx evaluation
kit and others). Driver is based on a cpufreq driver for 64-bit powermac
boxes with all pmac-dependant features removed and simple cleanup
applied.

Signed-off-by: Dmitry Eremin-Solenikov 
Signed-off-by: Benjamin Herrenschmidt

[CPUFREQ] Move compile for S3C64XX cpufreq to /drivers/cpufreq

2011-07-13T22:29:53+00:00

Cc: Mark Brown 
Signed-off-by: Kukjin Kim 
Signed-off-by: Dave Jones

[CPUFREQ] Remove some vi noise that escaped into the Makefile.

2011-07-13T22:29:53+00:00

[CPUFREQ] Move ARM Samsung cpufreq drivers to drivers/cpufreq/

2011-07-13T22:29:51+00:00

According to discussion of the ARM arch subsystem migration,
ARM cpufreq drivers move to drivers/cpufreq. So this patch
adds Kconfig.arm for ARM like x86 and adds Samsung S5PV210
and EXYNOS4210 cpufreq driver compile in there.
As a note, otherw will be moved.

Cc: Dave Jones 
Signed-off-by: Kukjin Kim 
Signed-off-by: Dave Jones

[CPUFREQ/S3C64xx] Move S3C64xx CPUfreq driver into drivers/cpufreq

2011-07-13T22:29:51+00:00

This is a straight code motion patch, there are no changes to the driver
itself. The Kconfig is left untouched as the ARM CPUfreq Kconfig is all
in one big block in arm/Kconfig and should be moved en masse rather than
being done piecemeal.

Signed-off-by: Mark Brown 
Signed-off-by: Dave Jones

cpufreq: make DB8500 cpufreq driver compile

2011-05-24T20:20:14+00:00

Concluding interface update and movement of the driver by making
the DB8500 cpufreq driver compile in the cpufreq subsystem.

Cc: Arnd Bergmann 
Acked-by: Dave Jones 
Signed-off-by: Linus Walleij

[CPUFREQ] Move x86 drivers to drivers/cpufreq/

2011-05-19T22:51:07+00:00

Signed-off-by: Dave Jones

[CPUFREQ] Conservative cpufreq governer

2005-06-01T02:03:47+00:00

A new cpufreq module, based on the ondemand one with my additional patches
just posted.  This one is more suitable for battery environments where its
probably more appealing to have the cpu freq gracefully increase and decrease
rather than flip between the min and max freq's.

N.B. Bruno Ducrot pointed out that the amd64's "do have unacceptable latency
between min and max freq transition, due to the step-by-step requirements
(200MHz IIRC)"; so AMD64 users would probably benefit from this too.

Signed-off-by: Alexander Clouter 
Signed-off-by: Dave Jones