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Subject[patch] i386: use C code for current_thread_info()
Using C code for current_thread_info() lets the compiler optimize it.
With gcc 4.0.2, kernel is smaller:

text data bss dec hex filename
3645212 555556 312024 4512792 44dc18 2.6.17-rc6-nb-post/vmlinux
3647276 555556 312024 4514856 44e428 2.6.17-rc6-nb/vmlinux
-------
-2064
Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>

--- 2.6.17-rc6-32.orig/include/asm-i386/thread_info.h
+++ 2.6.17-rc6-32/include/asm-i386/thread_info.h
@@ -84,17 +84,15 @@ struct thread_info {
#define init_stack (init_thread_union.stack)


+/* how to get the current stack pointer from C */
+register unsigned long current_stack_pointer asm("esp") __attribute_used__;
+
/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
- struct thread_info *ti;
- __asm__("andl %%esp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
- return ti;
+ return (struct thread_info *)(current_stack_pointer & ~(THREAD_SIZE - 1));
}

-/* how to get the current stack pointer from C */
-register unsigned long current_stack_pointer asm("esp") __attribute_used__;
-
/* thread information allocation */
#ifdef CONFIG_DEBUG_STACK_USAGE
#define alloc_thread_info(tsk) \
--
Chuck
-
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