Commit 57f2ffe1 authored Sep 15, 2014 by Heiko Carstens Committed by Martin Schwidefsky Nov 28, 2014

s390: remove diag 44 calls from cpu_relax()



Simplify cpu_relax() to a simple barrier(). Performance wise this doesn't
seem to make any big difference anymore, since nearly all lock variants
have directed yield semantics in the meantime.
Also this makes s390 behave like all other architectures.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 6ebdf1c7

arch/s390/include/asm/processor.h

+0 −2

Original line number	Original line	Diff line number	Diff line
	@@ -217,8 +217,6 @@ static inline unsigned short stap(void)
	*/		*/
	static inline void cpu_relax(void)		static inline void cpu_relax(void)
	{		{
	if (MACHINE_HAS_DIAG44)
	asm volatile("diag 0,0,68");
	barrier();		barrier();
	}		}