Commit 1cfc05cb authored Nov 09, 2015 by Vineet Gupta

ARC: cpu_relax() to be compiler barrier even for UP

cpu_relax() on ARC has been barrier only for SMP (and no-op for UP). Per
recent discussions, it is safer to make it a compiler barrier
unconditionally.

Link: http://lkml.kernel.org/r/53A7D3AA.9020100@synopsys.com


Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

parent a6416f57

arch/arc/include/asm/processor.h

+0 −4

Original line number	Diff line number	Diff line
		@@ -57,11 +57,7 @@ struct task_struct;
		* A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
		* get optimised away by gcc
		*/
		#ifdef CONFIG_SMP
		#define cpu_relax() __asm__ __volatile__ ("" : : : "memory")
		#else
		#define cpu_relax() do { } while (0)
		#endif

		#define cpu_relax_lowlatency() cpu_relax()

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