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Subject[RFC][PATCH 5/5] powerpc: Remove SYNC from _switch
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@infradead.org>
---
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

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