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hotplug / x86: Disable ARCH_CPU_PROBE_RELEASE on x86 

Commit d7c53c9e enabled ARCH_CPU_PROBE_RELEASE on x86 in order to
serialize CPU online/offline operations.  Although it is the config
option to enable CPU hotplug test interfaces, probe & release, it is
also the option to enable cpu_hotplug_driver_lock() as well.  Therefore,
this option had to be enabled on x86 with dummy arch_cpu_probe() and
arch_cpu_release().

Since then, lock_device_hotplug() was introduced to serialize CPU
online/offline & hotplug operations.  Therefore, this config option
is no longer required for the serialization.  This patch disables
this config option on x86 and revert the changes made by commit
d7c53c9e.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Toshi Kani 2013-08-29 18:22:08 -06:00 committed by Rafael J. Wysocki
parent 574b851e99
commit 1cad5e9a39
2 changed files with 0 additions and 25 deletions
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4
arch/x86/Kconfig
View File

@ -254,10 +254,6 @@ config ARCH_HWEIGHT_CFLAGS
default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
config ARCH_CPU_PROBE_RELEASE
def_bool y
depends on HOTPLUG_CPU
config ARCH_SUPPORTS_UPROBES
def_bool y

21
arch/x86/kernel/smpboot.c
View File

@ -82,27 +82,6 @@
/* State of each CPU */
DEFINE_PER_CPU(int, cpu_state) = { 0 };
#ifdef CONFIG_HOTPLUG_CPU
/*
* We need this for trampoline_base protection from concurrent accesses when
* off- and onlining cores wildly.
*/
static DEFINE_MUTEX(x86_cpu_hotplug_driver_mutex);
void cpu_hotplug_driver_lock(void)
{
mutex_lock(&x86_cpu_hotplug_driver_mutex);
}
void cpu_hotplug_driver_unlock(void)
{
mutex_unlock(&x86_cpu_hotplug_driver_mutex);
}
ssize_t arch_cpu_probe(const char *buf, size_t count) { return -1; }
ssize_t arch_cpu_release(const char *buf, size_t count) { return -1; }
#endif
/* Number of siblings per CPU package */
int smp_num_siblings = 1;
EXPORT_SYMBOL(smp_num_siblings);