| From: |
| Gautham R Shenoy <ego@in.ibm.com> |
| To: |
| Joel Schopp <jschopp@austin.ibm.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Dipankar Sarma <dipankar@in.ibm.com> |
| Subject: |
| [PATCH v2 0/2] cpu: pseries: Offline state framework. |
| Date: |
| Fri, 28 Aug 2009 15:30:11 +0530 |
| Message-ID: |
| <20090828095741.10641.32053.stgit@sofia.in.ibm.com> |
| Cc: |
| Balbir Singh <balbir@in.ibm.com>,
Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
"Darrick J. Wong" <djwong@us.ibm.com> |
| Archive‑link: | |
Article |
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.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
