[IA64] minor performance tune-up in ia64_switch_to
The reenabling of psr.ic should really belong to dtr mapping code block.
It make the fall through code fast since it doesn't need to execute the
predicated-off instruction. Logically make more sense as well since psr.ic
was turned off in .map code block.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S
index 9be53e1..3c88210 100644
--- a/arch/ia64/kernel/entry.S
+++ b/arch/ia64/kernel/entry.S
@@ -204,9 +204,6 @@
(p6) br.cond.dpnt .map
;;
.done:
-(p6) ssm psr.ic // if we had to map, reenable the psr.ic bit FIRST!!!
- ;;
-(p6) srlz.d
ld8 sp=[r21] // load kernel stack pointer of new task
mov IA64_KR(CURRENT)=in0 // update "current" application register
mov r8=r13 // return pointer to previously running task
@@ -234,6 +231,9 @@
mov IA64_KR(CURRENT_STACK)=r26 // remember last page we mapped...
;;
itr.d dtr[r25]=r23 // wire in new mapping...
+ ssm psr.ic // reenable the psr.ic bit
+ ;;
+ srlz.d
br.cond.sptk .done
END(ia64_switch_to)