From 1cad5e9a3978d182aa9b0e909fb0379da5ba45af Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Thu, 29 Aug 2013 18:22:08 -0600 Subject: [PATCH] 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 Acked-by: Yasuaki Ishimatsu Signed-off-by: Rafael J. Wysocki --- arch/x86/Kconfig | 4 ---- arch/x86/kernel/smpboot.c | 21 --------------------- 2 files changed, 25 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index ee2fb9d..dcdb513 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -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 diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 6cacab6..e73b3f5 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -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); -- 2.7.4