Re: [Qemu-devel] passing translated address out in QEMU

[Wei-Ren Chen]

> >> not too sure how much impact inlined lookup has on the performance.
> >> since i disabled it, next step i would just get rid of that piece of
> >> generated assembly, as it is no good for icache ( generated for every
> >> memory operation).
> >
> >   You can run a benchmark inside your guest. I guess if you run a
> > long-running benchmark, you can see performance degradation. If software
> > tlb hit, you can get the value of guest memory in the code cache
> > with a few host instructions. Disabling software tlb lookup, every guest
> > memory access will call a helper function which takes a lot of time.
> > What you mean by "get rid of that piece of generated assembly"?
> 
> every inlined TLB lookup has ~10 instructions .

  I still don't think remove inline tlb lookup will improve anything.
True, the inline tlb lookup will take some space on icache, but I
believe it's not a big deal since you're on a x86 host.

Regards,
chenwj

-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj