[PATCH] [28/30] i386: avoid redundant preempt_disable in __unlazy_fpu

From: Andi Kleen
Date: Tue May 01 2007 - 00:00:36 EST



From: Jan Kiszka <jan.kiszka@xxxxxx>

There are two callers of __unlazy_fpu, unlazy_fpu and __switch_to, and
none of them appear to require additional preempt_disable/enable here.
Let's open-code save_init_fpu in __unlazy_fpu to save a few ops.

Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxx>

---
include/asm-i386/i387.h | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

Index: linux/include/asm-i386/i387.h
===================================================================
--- linux.orig/include/asm-i386/i387.h
+++ linux/include/asm-i386/i387.h
@@ -74,11 +74,12 @@ static inline void __save_init_fpu( stru
task_thread_info(tsk)->status &= ~TS_USEDFPU;
}

-#define __unlazy_fpu( tsk ) do { \
- if (task_thread_info(tsk)->status & TS_USEDFPU) \
- save_init_fpu( tsk ); \
- else \
- tsk->fpu_counter = 0; \
+#define __unlazy_fpu( tsk ) do { \
+ if (task_thread_info(tsk)->status & TS_USEDFPU) { \
+ __save_init_fpu(tsk); \
+ stts(); \
+ } else \
+ tsk->fpu_counter = 0; \
} while (0)

#define __clear_fpu( tsk ) \
-
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