diff options
Diffstat (limited to 'arch/x86/include/asm/mmu_context.h')
| -rw-r--r-- | arch/x86/include/asm/mmu_context.h | 20 |
1 files changed, 0 insertions, 20 deletions
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index b7135e92e571..a3e1c72a3ab9 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -12,7 +12,6 @@ #include <asm/pgalloc.h> #include <asm/tlbflush.h> #include <asm/paravirt.h> -#include <asm/mpx.h> #include <asm/debugreg.h> extern atomic64_t last_mm_ctx_id; @@ -275,25 +274,6 @@ static inline bool is_64bit_mm(struct mm_struct *mm) static inline void arch_unmap(struct mm_struct *mm, unsigned long start, unsigned long end) { - /* - * mpx_notify_unmap() goes and reads a rarely-hot - * cacheline in the mm_struct. That can be expensive - * enough to be seen in profiles. - * - * The mpx_notify_unmap() call and its contents have been - * observed to affect munmap() performance on hardware - * where MPX is not present. - * - * The unlikely() optimizes for the fast case: no MPX - * in the CPU, or no MPX use in the process. Even if - * we get this wrong (in the unlikely event that MPX - * is widely enabled on some system) the overhead of - * MPX itself (reading bounds tables) is expected to - * overwhelm the overhead of getting this unlikely() - * consistently wrong. - */ - if (unlikely(cpu_feature_enabled(X86_FEATURE_MPX))) - mpx_notify_unmap(mm, start, end); } /* |