On Tuesday 08 August 2006 07:09, Paul Mackerras wrote: > Andrew Morton writes:
[adding linux-arch; talking about doing extensible per cpu areas by prereserving virtual space and then later fill it up as needed] > > > Drawback would be some more TLB misses. > > > > yup. On some (important) architectures - I'm not sure which architectures > > do the bigpage-for-kernel trick. > > I looked at optimizing the per-cpu data accessors on PowerPC and only > ever saw fractions of a percent change in overall performance, which > says to me that we don't actually use per-cpu data all that much. So > unless you make per-cpu data really really slow, I doubt that we'll > see any significant performance difference. The main problem is that we would need a "vmalloc reserve first; allocate pages later" interface. On x86 it would be easy by just splitting up vmalloc/vmap a bit again. Does anybody else see problems with implementing that on any other architecture? This wouldn't be truly demand paged, just pages initialized on allocation. -Andi - To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
