Messages in this thread Patch in this message | | | From | riel@redhat ... | Subject | [RFC PATCH 03/11] x86,fpu: move __thread_fpu_begin to when the task has the fpu | Date | Sun, 11 Jan 2015 16:46:25 -0500 |
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From: Rik van Riel <riel@redhat.com>
Move the call to __thread_fpu_begin, which in turn calls __thread_set_has_fpu, to a spot where the task actually has the FPU.
This is in preparation for the next patch.
This changeset introduces an extraneous clts() call when switching from one FPU-using task to another FPU-using task in non-eager FPU switching mode. The next patch gets rid of that.
Signed-off-by: Rik van Riel <riel@redhat.com> --- arch/x86/include/asm/fpu-internal.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index 5f8f971..27556f4 100644 --- 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); } -- 1.9.3
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