OpenCloudOS-Kernel/arch/sparc
Srivatsa S. Bhat 1e0b0c4c6b sparc, sysfs: Fix CPU hotplug callback registration
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

	get_online_cpus();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	register_cpu_notifier(&foobar_cpu_notifier);

	put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Instead, the correct and race-free way of performing the callback
registration is:

	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	/* Note the use of the double underscored version of the API */
	__register_cpu_notifier(&foobar_cpu_notifier);

	cpu_notifier_register_done();

Fix the sysfs code in sparc by using this latter form of callback
registration.

Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-20 13:43:41 +01:00
..
boot sparc: Fix piggyback with newer binutils. 2012-12-03 11:24:25 -08:00
configs perf: Remove PERF_COUNTERS config option 2012-04-26 13:52:52 +02:00
crypto sparc64: Set CRYPTO_TFM_REQ_MAY_SLEEP consistently in CAMELLIA code. 2012-12-19 15:44:31 -08:00
include sparc: Hook up sched_setattr and sched_getattr syscalls. 2014-01-29 00:45:06 -08:00
kernel sparc, sysfs: Fix CPU hotplug callback registration 2014-03-20 13:43:41 +01:00
lib sparc64: Make PAGE_OFFSET variable. 2013-11-12 15:22:34 -08:00
math-emu sparc64: Make montmul/montsqr/mpmul usable in 32-bit threads. 2012-10-26 15:18:37 -07:00
mm sparc32: make copy_to/from_user_page() usable from modular code 2014-02-19 19:49:48 -05:00
net bpf: do not use reciprocal divide 2014-01-15 17:02:08 -08:00
oprofile sparc: using HZ needs an include of linux/param.h 2009-10-05 00:46:08 -07:00
power sparc64: Hibernation support 2013-03-20 11:06:54 -07:00
prom sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
Kbuild sparc64: Add SHA1 driver making use of the 'sha1' instruction. 2012-08-20 15:08:49 -07:00
Kconfig sparc32: fix build failure for arch_jump_label_transform 2014-02-19 19:49:48 -05:00
Kconfig.debug lib: consolidate DEBUG_STACK_USAGE option 2011-05-25 08:39:54 -07:00
Makefile sparc64: Hibernation support 2013-03-20 11:06:54 -07:00