RE: [Xen-ia64-devel] CONFIG_DOMAIN0_CONTIGUOUS in domain.c

["Dong, Eddie" <eddie.dong@xxxxxxxxx>]

Magenheimer, Dan (HP Labs Fort Collins) wrote:
> to VP.  HOWEVER... it may be possible and desirable
> for much of Isaku's work to support both VP and P==M.
> For non-I/O code, CONFIG_DOMAIN0_CONTIGUOUS could be
> used (or possibly renamed) to select VP or P==M at
> compile-time, at least until the conversion to VP+DMA
> is complete.  This would allow at least some of Isaku's
As if eventually we will remove this code, putting an compile option now
is OK IMO. But I think the default one should be #undefed by some
pre-cleanip patch now so that people can find issues earlier if there
have. 
#undef this one can support no matter p==m or p!=m, while #define this
can only support p==m. Yes maybe we will see 0.5% performance
degradation with #undef, but this is a functionality must as we all go
toward p!=m :-(
After the whole p2m/VP patch comes out, we can then do more performance
tuning :-)
Eddie

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