Re: [PATCH 2/4] locking/rtmutex: Use cmp-cmpxchg

From: Jason Low
Date: Mon Jun 15 2015 - 21:00:46 EST


On Mon, Jun 15, 2015 at 12:37 PM, Davidlohr Bueso <dave@xxxxxxxxxxxx> wrote:
> On Mon, 2015-06-15 at 11:34 -0700, Jason Low wrote:
>> The CCAS technique was typically used in the slow paths for those
>> other locks, where the chance of the operation returning false is
>> higher.
>
> That is true. Although I really want to use it in patch 4, I guess I
> could move the check in there, and thus avoid having it in the fastpath.

I agree, that way, we only have the extra check in cases where it is
beneficial, like in the optimistic spin loop.

Jason
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