linux/drivers/base
Gautham R Shenoy 51badebdcf powerpc/pseries: Serialize cpu hotplug operations during deactivate Vs deallocate
Currently the cpu-allocation/deallocation process comprises of two steps:
- Set the indicators and to update the device tree with DLPAR node
  information.

- Online/offline the allocated/deallocated CPU.

This is achieved by writing to the sysfs tunables "probe" during allocation
and "release" during deallocation.

At the sametime, the userspace can independently online/offline the CPUs of
the system using the sysfs tunable "online".

It is quite possible that when a userspace tool offlines a CPU
for the purpose of deallocation and is in the process of updating the device
tree, some other userspace tool could bring the CPU back online by writing to
the "online" sysfs tunable thereby causing the deallocate process to fail.

The solution to this is to serialize writes to the "probe/release" sysfs
tunable with the writes to the "online" sysfs tunable.

This patch employs a mutex to provide this serialization, which is a no-op on
all architectures except PPC_PSERIES

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Acked-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-12-09 17:09:36 +11:00
..
power PM: Remove some debug messages producing too much noise 2009-11-03 11:18:18 +01:00
attribute_container.c driver core: struct device - replace bus_id with dev_name(), dev_set_name() 2009-01-06 10:44:31 -08:00
base.h Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev 2009-09-15 09:50:49 -07:00
bus.c Driver core: allow certain drivers prohibit bind/unbind via sysfs 2009-10-30 14:59:51 -07:00
class.c Driver core: Add support for compatibility classes 2009-09-15 09:50:48 -07:00
core.c Driver-Core: extend devnode callbacks to provide permissions 2009-09-19 12:50:38 -07:00
cpu.c powerpc/pseries: Serialize cpu hotplug operations during deactivate Vs deallocate 2009-12-09 17:09:36 +11:00
dd.c Driver core: move dev_get/set_drvdata to drivers/base/dd.c 2009-09-15 09:50:47 -07:00
devres.c devres: WARN() and return, don't crash on device_del() of uninitialized device 2009-07-12 13:02:09 -07:00
devtmpfs.c Driver-Core: extend devnode callbacks to provide permissions 2009-09-19 12:50:38 -07:00
dma-coherent.c driver-core: move dma-coherent.c from kernel to driver/base 2009-09-15 09:50:47 -07:00
dma-mapping.c devres: device resource management 2007-02-09 17:39:36 -05:00
driver.c Driver core: fix driver_register() return value 2009-10-30 14:59:51 -07:00
firmware_class.c driver core: firmware_class:fix memory leak of page pointers array 2009-07-28 13:45:22 -07:00
firmware.c firmware: change firmware_kset to firmware_kobj 2008-01-24 20:40:23 -08:00
hypervisor.c kobject: convert /sys/hypervisor to use kobject_create 2008-01-24 20:40:15 -08:00
init.c Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev 2009-09-15 09:50:49 -07:00
iommu.c drivers/base/iommu.c: add missing includes 2009-05-06 16:36:10 -07:00
isa.c dma-mapping: replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24) 2009-04-07 08:31:12 -07:00
Kconfig Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev 2009-09-15 09:50:49 -07:00
Makefile Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev 2009-09-15 09:50:49 -07:00
map.c [PATCH] kobj_map semaphore to mutex conversion 2006-03-20 13:42:58 -08:00
memory.c mm: show node to memory section relationship with symlinks in sysfs 2009-01-06 15:59:00 -08:00
module.c Driver core: move the static kobject out of struct driver 2008-01-24 20:40:35 -08:00
node.c mm: oom analysis: add shmem vmstat 2009-09-22 07:17:27 -07:00
platform.c Driver core: allow certain drivers prohibit bind/unbind via sysfs 2009-10-30 14:59:51 -07:00
sys.c driver core: sysdev: do not send KOBJ_ADD uevent if kobject_init_and_add fails 2009-07-28 13:45:22 -07:00
topology.c cpumask: Use topology_core_cpumask()/topology_thread_cpumask() 2009-01-11 19:12:49 +01:00
transport_class.c SCSI: convert struct class_device to struct device 2008-04-19 19:10:33 -07:00