forked from Minki/linux
mainlining shenanigans
db50a74d81
If a CPU is entering a low power idle state where it doesn't lose any context, then there is no need to call cpu_pm_enter()/cpu_pm_exit(). Add a new macro(CPU_PM_CPU_IDLE_ENTER_RETENTION) to be used by cpuidle drivers when they are entering retention state. By not calling cpu_pm_enter and cpu_pm_exit we reduce the latency involved in entering and exiting the retention idle states. CPU_PM_CPU_IDLE_ENTER_RETENTION assumes that no state is lost and hence CPU PM notifiers will not be called. We may need a broader change if we need to support partial retention states effeciently. On ARM64 based Qualcomm Server Platform we measured below overhead for for calling cpu_pm_enter and cpu_pm_exit for retention states. workload: stress --hdd #CPUs --hdd-bytes 32M -t 30 Average overhead of cpu_pm_enter - 1.2us Average overhead of cpu_pm_exit - 3.1us Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Prashanth Prakash <pprakash@codeaurora.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> |
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arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.