Implement "current" with the PDA.

Use the pcurrent field in the PDA to implement the "current" macro.
This ends up compiling down to a single instruction to get the current
task.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <ak@suse.de>

---
 include/asm-i386/current.h |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff -r 5eb01c4f49fe include/asm-i386/current.h
--- a/include/asm-i386/current.h	Mon Sep 25 23:05:11 2006 -0700
+++ b/include/asm-i386/current.h	Mon Sep 25 23:05:12 2006 -0700
@@ -1,13 +1,14 @@
 #ifndef _I386_CURRENT_H
 #define _I386_CURRENT_H
 
-#include <linux/thread_info.h>
+#include <asm/pda.h>
+#include <linux/compiler.h>
 
 struct task_struct;
 
-static __always_inline struct task_struct * get_current(void)
+static __always_inline struct task_struct *get_current(void)
 {
-	return current_thread_info()->task;
+	return read_pda(pcurrent);
 }
  
 #define current get_current()