Re: [cpuops cmpxchg double V2 1/4] Generic support forthis_cpu_cmpxchg_double

From: Tejun Heo
Date: Fri Feb 25 2011 - 08:26:29 EST

On Fri, Feb 25, 2011 at 03:09:26PM +0200, Pekka Enberg wrote:
> On Fri, Jan 21, 2011 at 09:13:41AM -0800, H. Peter Anvin wrote:
> >>>We could do cmpxchg with a structure... the problem with a lon int
> >>>type is that Cristoph ran into bugs with __int128 on 64 bits.
> On 01/21/2011 09:19 AM, Tejun Heo wrote:
> >>But, IIRC, the problem with int128 was with passing it as parameter
> >>and return value. We don't have to do that. We'll be just using it
> >>as a data storage / container type. Or even that is broken?
> On 1/24/11 8:01 AM, H. Peter Anvin wrote:
> >Well, part of the point was to pass in registers.
> >
> >No idea on the data storage type.
> Ping? The current situation is that we're unable to merge a
> perfectly good SLUB performance optimization because we can't seem
> to agree on the this_cpu_cmpxchg_double() API.

I thought cl was preparing new version of the patchset. Christoph?

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