There is no point in disabling preemption and then disabling bottom halfs. Just disabling bottom halfs is sufficient as it implicitly disables preemption on !RT kernels.
Signed-off-by: Thomas Gleixner <[email protected]> --- arch/x86/include/asm/fpu/api.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -29,17 +29,18 @@ extern void fpregs_mark_activate(void); * A context switch will (and softirq might) save CPU's FPU registers to * fpu->state and set TIF_NEED_FPU_LOAD leaving CPU's FPU registers in * a random state. + * + * local_bh_disable() protects against both preemption and soft interrupts + * on !RT kernels. */ static inline void fpregs_lock(void) { - preempt_disable(); local_bh_disable(); } static inline void fpregs_unlock(void) { local_bh_enable(); - preempt_enable(); } #ifdef CONFIG_X86_DEBUG_FPU
