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Commit 02326223 authored by Kenneth W Chen's avatar Kenneth W Chen Committed by Tony Luck
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[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: default avatarKen Chen <kenneth.w.chen@intel.com>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 295bd892

arch/ia64/kernel/entry.S

+3 −3
Original line number Diff line number Diff line
@@ -204,9 +204,6 @@ GLOBAL_ENTRY(ia64_switch_to) 
(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 @@ GLOBAL_ENTRY(ia64_switch_to) 
	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)