ARCv2: spinlock/rwlock/atomics: reduce 1 instruction in exponential backoff
authorVineet Gupta <vgupta@synopsys.com>
Fri, 7 Aug 2015 07:31:39 +0000 (13:01 +0530)
committerVineet Gupta <vgupta@synopsys.com>
Fri, 7 Aug 2015 08:26:16 +0000 (13:56 +0530)
commit10971638701dedadb58c88ce4d31c9375b224ed6
treeb210f8710277b0ae74ea5c8143c3c9f6b5dc5bd1
parent87ce62802f7a3553234ebf1ae7cd52c8bf272fb9
ARCv2: spinlock/rwlock/atomics: reduce 1 instruction in exponential backoff

The increment of delay counter was 2 instructions:
Arithmatic Shfit Left (ASL) + set to 1 on overflow

This can be done in 1 using ROtate Left (ROL)

Suggested-by: Nigel Topham <ntopham@synopsys.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
arch/arc/include/asm/atomic.h
arch/arc/include/asm/spinlock.h