As a first step towards improving the power awareness of the scheduler, this patch enables a "dumb" state where all power management is turned off. Whatever additionally we put into the kernel for cpu power management must do better than this in terms of performance as well as powersavings. This will enable us to benchmark and optimize the power aware scheduler from scratch.If we are to benchmark it against the performance of the existing design, we will get sufficiently distracted by the performance numbers and get steered away from a sane design.
Signed-off-by: Preeti U Murthy preeti@linux.vnet.ibm.com ---
arch/powerpc/Kconfig | 1 + arch/powerpc/platforms/powernv/Kconfig | 12 ++++++------ drivers/cpufreq/Kconfig | 2 ++ drivers/cpuidle/Kconfig | 2 ++ kernel/Kconfig.sched | 11 +++++++++++ 5 files changed, 22 insertions(+), 6 deletions(-) create mode 100644 kernel/Kconfig.sched
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 80b94b0..b7fe36a 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -301,6 +301,7 @@ config HIGHMEM
source kernel/Kconfig.hz source kernel/Kconfig.preempt +source kernel/Kconfig.sched source "fs/Kconfig.binfmt"
config HUGETLB_PAGE_SIZE_VARIABLE diff --git a/arch/powerpc/platforms/powernv/Kconfig b/arch/powerpc/platforms/powernv/Kconfig index 45a8ed0..b0ef8b1 100644 --- a/arch/powerpc/platforms/powernv/Kconfig +++ b/arch/powerpc/platforms/powernv/Kconfig @@ -11,12 +11,12 @@ config PPC_POWERNV select PPC_UDBG_16550 select PPC_SCOM select ARCH_RANDOM - select CPU_FREQ - select CPU_FREQ_GOV_PERFORMANCE - select CPU_FREQ_GOV_POWERSAVE - select CPU_FREQ_GOV_USERSPACE - select CPU_FREQ_GOV_ONDEMAND - select CPU_FREQ_GOV_CONSERVATIVE + select CPU_FREQ if !SCHED_POWER + select CPU_FREQ_GOV_PERFORMANCE if CPU_FREQ + select CPU_FREQ_GOV_POWERSAVE if CPU_FREQ + select CPU_FREQ_GOV_USERSPACE if CPU_FREQ + select CPU_FREQ_GOV_ONDEMAND if CPU_FREQ + select CPU_FREQ_GOV_CONSERVATIVE if CPU_FREQ select PPC_DOORBELL default y
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig index ffe350f..8976fd6 100644 --- a/drivers/cpufreq/Kconfig +++ b/drivers/cpufreq/Kconfig @@ -2,6 +2,7 @@ menu "CPU Frequency scaling"
config CPU_FREQ bool "CPU Frequency scaling" + depends on !SCHED_POWER help CPU Frequency scaling allows you to change the clock speed of CPUs on the fly. This is a nice method to save power, because @@ -12,6 +13,7 @@ config CPU_FREQ (see below) after boot, or use a userspace tool.
For details, take a look at file:Documentation/cpu-freq. + This feature will turn off if power aware scheduling is enabled.
If in doubt, say N.
diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig index 32748c3..2c4ac79 100644 --- a/drivers/cpuidle/Kconfig +++ b/drivers/cpuidle/Kconfig @@ -3,6 +3,7 @@ menu "CPU Idle" config CPU_IDLE bool "CPU idle PM support" default y if ACPI || PPC_PSERIES + depends on !SCHED_POWER select CPU_IDLE_GOV_LADDER if (!NO_HZ && !NO_HZ_IDLE) select CPU_IDLE_GOV_MENU if (NO_HZ || NO_HZ_IDLE) help @@ -11,6 +12,7 @@ config CPU_IDLE governors that can be swapped during runtime.
If you're using an ACPI-enabled platform, you should say Y here. + This feature will turn off if power aware scheduling is enabled.
if CPU_IDLE
diff --git a/kernel/Kconfig.sched b/kernel/Kconfig.sched new file mode 100644 index 0000000..374454c --- /dev/null +++ b/kernel/Kconfig.sched @@ -0,0 +1,11 @@ +menu "Power Aware Scheduling" + +config SCHED_POWER + bool "Power Aware Scheduler" + default n + help + Select this to enable the new power aware scheduler. +endmenu + + +