Messages in this thread | | | Date | Mon, 3 Aug 2015 13:43:52 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 6/6] ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle |
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On Mon, Aug 03, 2015 at 03:33:08PM +0530, Vineet Gupta wrote: > A spin lock could be available momentarily, but the SCOND to actually > acquire it might still fail due to concurrent update from other core(s). > To elide hardware lock, the sequence is retried after a "delay" which is > increased expoenntially to get a nice backoff behaviour. > > However, this could cause the delay counter to get to a high value. Thus > when the next spin cycle restarts, reset the counter back to starting > value of 1.
Cute.. fwiw, did you look at what Sparc64 does?
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