Create cpu_smt_enabled static key used for enabling SMT specific code paths.
Signed-off-by: Tim Chen <tim.c.c...@linux.intel.com> --- include/linux/cpu.h | 1 + kernel/cpu.c | 12 ++++++++++-- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 218df7f..b54f085 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -188,5 +188,6 @@ static inline void cpu_smt_disable(bool force) { } static inline void cpu_smt_check_topology_early(void) { } static inline void cpu_smt_check_topology(void) { } #endif +DECLARE_STATIC_KEY_TRUE(cpu_smt_enabled); #endif /* _LINUX_CPU_H_ */ diff --git a/kernel/cpu.c b/kernel/cpu.c index 3adecda..03170c8 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -349,6 +349,8 @@ EXPORT_SYMBOL_GPL(cpu_hotplug_enable); #ifdef CONFIG_HOTPLUG_SMT enum cpuhp_smt_control cpu_smt_control __read_mostly = CPU_SMT_ENABLED; EXPORT_SYMBOL_GPL(cpu_smt_control); +DEFINE_STATIC_KEY_TRUE(cpu_smt_enabled); +EXPORT_SYMBOL_GPL(cpu_smt_enabled); static bool cpu_smt_available __read_mostly; @@ -364,6 +366,7 @@ void __init cpu_smt_disable(bool force) } else { cpu_smt_control = CPU_SMT_DISABLED; } + static_branch_disable(&cpu_smt_enabled); } /* @@ -373,8 +376,10 @@ void __init cpu_smt_disable(bool force) */ void __init cpu_smt_check_topology_early(void) { - if (!topology_smt_supported()) + if (!topology_smt_supported()) { cpu_smt_control = CPU_SMT_NOT_SUPPORTED; + static_branch_disable(&cpu_smt_enabled); + } } /* @@ -386,8 +391,10 @@ void __init cpu_smt_check_topology_early(void) */ void __init cpu_smt_check_topology(void) { - if (!cpu_smt_available) + if (!cpu_smt_available) { cpu_smt_control = CPU_SMT_NOT_SUPPORTED; + static_branch_disable(&cpu_smt_enabled); + } } static int __init smt_cmdline_disable(char *str) @@ -2072,6 +2079,7 @@ static int cpuhp_smt_enable(void) cpu_maps_update_begin(); cpu_smt_control = CPU_SMT_ENABLED; + static_branch_enable(&cpu_smt_enabled); arch_smt_update(); for_each_present_cpu(cpu) { /* Skip online CPUs and CPUs on offline nodes */ -- 2.9.4