Messages in this thread Patch in this message |  | | From | riel@redhat ... | Subject | [PATCH 5/8] x86,fpu: introduce task_disable_lazy_fpu_restore helper | Date | Fri, 6 Feb 2015 15:02:02 -0500 |
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From: Rik van Riel <riel@redhat.com>
Currently there are a few magic assignments sprinkled through the code that disable lazy FPU state restoring, some more effective than others, and all equally mystifying.
It would be easier to have a helper to explicitly disable lazy FPU state restoring for a task.
Signed-off-by: Rik van Riel <riel@redhat.com> --- arch/x86/include/asm/fpu-internal.h | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index 439ac3921a1e..c1f66261ad12 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -79,6 +79,16 @@ static inline void __cpu_disable_lazy_restore(unsigned int cpu) per_cpu(fpu_owner_task, cpu) = NULL; } +/* + * Used to indicate that the FPU state in memory is newer than the FPU + * state in registers, and the FPU state should be reloaded next time the + * task is run. Only safe on the current task, or non-running tasks. + */ +static inline void task_disable_lazy_fpu_restore(struct task_struct *tsk) +{ + tsk->thread.fpu.last_cpu = ~0; +} + static inline int fpu_lazy_restore(struct task_struct *new, unsigned int cpu) { return new == this_cpu_read_stable(fpu_owner_task) && -- 1.9.3
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