Messages in this thread | | | Subject | [PATCH v2 0/2] cpu: pseries: Offline state framework. | From | Gautham R Shenoy <> | Date | Fri, 28 Aug 2009 15:30:11 +0530 |
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Hi,
This is the version 2 of the patch series to provide a cpu-offline framework that enables the administrators choose the state the offline CPU must be put into when multiple such states are exposed by the underlying architecture.
Version 1 of the Patch can be found here: http://lkml.org/lkml/2009/8/6/236
The patch-series exposes the following sysfs tunables to allow the system-adminstrator to choose the state of a CPU:
To query the available hotplug states, one needs to read the sysfs tunable: /sys/devices/system/cpu/cpu<number>/available_hotplug_states To query or set the current state, on needs to read/write the sysfs tunable: /sys/devices/system/cpu/cpu<number>/current_states
The patchset ensures that the writes to the "current_state" sysfs file are serialized against the writes to the "online" file.
This patchset also contains the offline state driver implemented for pSeries. For pSeries, we define three available_hotplug_states. They are:
online: The processor is online.
deallocate: This is the the default behaviour when the cpu is offlined even in the absense of this driver. The CPU would call make an rtas_stop_self() call and hand over the CPU back to the resource pool, thereby effectively deallocating that vCPU from the LPAR. NOTE: This would result in a configuration change to the LPAR which is visible to the outside world.
deactivate: This cedes the vCPU to the hypervisor which in turn can put the vCPU time to the best use. NOTE: This option DOES NOT result in a configuration change and the vCPU would be still entitled to the LPAR to which it earlier belong to.
Awaiting your feedback. ---
Gautham R Shenoy (2): cpu: Implement cpu-offline-state driver for pSeries. cpu: Offline state Framework.
arch/powerpc/platforms/pseries/Makefile | 2 arch/powerpc/platforms/pseries/hotplug-cpu.c | 76 +++++++++- arch/powerpc/platforms/pseries/offline_driver.c | 161 +++++++++++++++++++++ arch/powerpc/platforms/pseries/offline_driver.h | 20 +++ arch/powerpc/platforms/pseries/smp.c | 17 ++ drivers/base/cpu.c | 176 ++++++++++++++++++++++- include/linux/cpu.h | 30 ++++ 7 files changed, 465 insertions(+), 17 deletions(-) create mode 100644 arch/powerpc/platforms/pseries/offline_driver.c create mode 100644 arch/powerpc/platforms/pseries/offline_driver.h
-- Thanks and Regards gautham.
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