Messages in this thread | | | Date | Mon, 02 Jun 2014 13:33:34 -0400 | From | Waiman Long <> | Subject | Re: [PATCH v2] introduce atomic_pointer to fix a race condition in cancelable mcs spinlocks |
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On 06/02/2014 12:30 PM, Peter Zijlstra wrote: > On Mon, Jun 02, 2014 at 06:25:25PM +0200, Peter Zijlstra wrote: >> I'm almost inclined to just exclude parisc from using opt spinning. >> >> That said, this patch still doesn't address the far more interesting >> problem of actually finding these issues for these few weird archs. > So why do these archs provide xchg() and cmpxchg() at all? Wouldn't it > be much simpler if archs that cannot sanely do this, not provide these > primitives at all?
I believe xchg() and cmpxchg() are used in quite a number of places within the generic kernel code. So kernel compilation will fail if those APIs aren't provided by an architecture.
-Longman
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