Re: [this_cpu_xx V7 0/8] Per cpu atomics in core allocators andcleanup

[Mathieu Desnoyers]

* Christoph Lameter (cl@xxxxxxxxxxxxxxxxxxxx) wrote:
> On Thu, 17 Dec 2009, Mathieu Desnoyers wrote:
> 
> > Some quick test on my Intel Xeon E5405:
> >
> > local cmpxchg:  14 cycles
> > xchg:           18 cycles
> >
> > So yes, indeed, the non-LOCK prefixed local cmpxchg seems a bit faster
> > than the xchg, given the latter has an implied LOCK prefix.
> >
> > Code used for local cmpxchg:
> >                 old = var;
> >                 do {
> >                         ret = cmpxchg_local(&var, old, 4);
> >                         if (likely(ret == old))
> >                                 break;
> >                         old = ret;
> >                 } while (1);
> >
> 
> Great. Could you also put that into "patch-format"?
> 

Sure, can you point me to a git tree I should work on top of which
includes the per cpu infrastructure to extend ?

Mathieu


-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/