Messages in this thread | | | Date | Fri, 6 Jun 2014 09:29:24 +0200 | From | Peter Zijlstra <> | Subject | Re: regarding use of various cmpxchg* API |
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On Thu, Jun 05, 2014 at 06:44:37PM -0400, Pranith Kumar wrote: > Hi Peter, Ingo, > > I see that in the drivers there are the following types of cmpxchg API: > > __cmpxchg64()
That shouldn't really be used, and its only used in intel-iommu.c.
> atomic_cmpxchg() > atomic64_cmpxchg() > atomic_long_cmpxchg()
They're part of the atomic*_t family and should be used on their respective types, no point in changing that.
> local_cmpxchg()(in kernel/events/ring_buffer.c)
This is part of the local_t API, also no real point to change that.
> this_cpu_cmpxchg()
This is part of the this_cpu*() family, and there's no way you can generate the same code using the below to.
> cmpxchg() > cmpxchg_local()
Which leaves these, which are used in all other cases.
> Since cmpxchg() internally handles the width, do you think it makes > sense to replace the above uses of cmpxchg with the document API > (cmpxchg, atomic_cmpxchg, cmpxchg_local)? > > I am willing to do this and wanted to know if it something you think > is worth pursuing.
Don't think that's useful. If you really want to go do something, try the annotation I suggested to get the parisc/sparc32 things correct again. Add the __atomic sparse address space and the store()/load() accessors. [unhandled content-type:application/pgp-signature] | |