aha/include
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
..
acpi ACPI: remove acpi_device_uid() and related stuff 2009-09-25 15:09:49 -04:00
asm-generic fcntl: rename F_OWNER_GID to F_OWNER_PGRP 2009-11-17 17:40:33 -08:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2009-09-11 09:38:37 -07:00
drm Merge branch 'drm-next' of ../drm-next into drm-linus 2009-10-08 14:03:05 +10:00
keys RxRPC: Use uX/sX rather than uintX_t/intX_t types 2009-09-16 00:01:13 -07:00
linux powerpc/pseries: Serialize cpu hotplug operations during deactivate Vs deallocate 2009-12-09 17:09:36 +11:00
math-emu
media V4L/DVB (13019): video: initial support for ADV7180 2009-09-19 00:53:39 -03:00
mtd
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2009-11-18 14:54:45 -08:00
pcmcia PM / yenta: Split resume into early and late parts (rev. 4) 2009-11-03 10:54:58 +01:00
rdma trivial: fix typo "to to" in multiple files 2009-09-21 15:14:55 +02:00
rxrpc
scsi [SCSI] Fix incorrect reporting of host protection capabilities 2009-11-06 11:50:52 -06:00
sound
trace Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block 2009-10-04 12:39:14 -07:00
video davinci-fb-frame-buffer-driver-for-ti-da8xx-omap-l1xx-v4 2009-09-23 07:39:51 -07:00
xen
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