[RFC][PATCH 5/5] powerpc: Remove SYNC from _switch

[Peter Zijlstra]

Now that the scheduler's rq->lock is RCsc and thus provides full
transitivity between scheduling actions. And since we cannot migrate
current, a task needs a switch-out and a switch-in in order to
migrate, in which case the RCsc provides all the ordering we need.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
 arch/powerpc/kernel/entry_64.S |    8 --------
 1 file changed, 8 deletions(-)

--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -488,14 +488,6 @@ _GLOBAL(_switch)
 	std	r23,_CCR(r1)
 	std	r1,KSP(r3)	/* Set old stack pointer */
 
-#ifdef CONFIG_SMP
-	/* We need a sync somewhere here to make sure that if the
-	 * previous task gets rescheduled on another CPU, it sees all
-	 * stores it has performed on this one.
-	 */
-	sync
-#endif /* CONFIG_SMP */
-
 	/*
 	 * If we optimise away the clear of the reservation in system
 	 * calls because we know the CPU tracks the address of the