lkml.org 
[lkml]   [2015]   [Jan]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC PATCH 03/11] x86,fpu: move __thread_fpu_begin to when the task has the fpu
On 01/11, riel@redhat.com wrote:
>
> --- a/arch/x86/include/asm/fpu-internal.h
> +++ b/arch/x86/include/asm/fpu-internal.h
> @@ -420,7 +420,6 @@ static inline void switch_fpu_prepare(struct task_struct *old, struct task_struc
> if (preload) {
> new->thread.fpu_counter++;
> set_thread_flag(TIF_LOAD_FPU);
> - __thread_set_has_fpu(new);
> prefetch(new->thread.fpu.state);
> } else if (!use_eager_fpu())
> stts();
> @@ -436,7 +435,6 @@ static inline void switch_fpu_prepare(struct task_struct *old, struct task_struc
> prefetch(new->thread.fpu.state);
> set_thread_flag(TIF_LOAD_FPU);
> }
> - __thread_fpu_begin(new);
> }
> /* else: CR0.TS is still set from a previous FPU switch */
> }
> @@ -451,6 +449,7 @@ static inline void switch_fpu_prepare(struct task_struct *old, struct task_struc
> static inline void switch_fpu_finish(struct task_struct *new)
> {
> if (test_and_clear_thread_flag(TIF_LOAD_FPU)) {
> + __thread_fpu_begin(new);
> if (unlikely(restore_fpu_checking(new)))
> drop_init_fpu(new);
> }

Then perhaps it makes sense to move fpu_lazy_restore() to fpu_finish() too ?

Either way, afaics we do not need use_eager_fpu() before fpu_lazy_restore(),
and this reminds me that every use_eager_fpu() check in switch_fpu_prepare()
looks confusing.

Oleg.



\
 
 \ /
  Last update: 2015-01-13 17:01    [W:0.318 / U:0.440 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site