Re: [f-cpu] TLB design

[Martin Devera <devik@cdi.cz>]

> > Counter is not useable. It is because you often got multiple accesses
> > in burst and this would make it overflow quicly. Rather you need to
> > count these burst to get LFU replacement strategy which is emulated
> > in 2.4.10 and latest BSDs.
> > What would help and what is pain in current linux mm is timestamp of
> > last access. But yes - it is unfortunately space expensive.
> > devik
>
> Oh well i supose we can have a saturate counter ? no, i'm joking :)
>
> Usually a SW TLB raises an exception when a miss cache occurs, so we can
> timestamped the page discarded (linux for example have a info block per
> physical page) and use it when a slow timer is walking the info blocks to
> lookup for a ideal candidate (timestamp least recent I think). I suppose of
> course that there is much more physical pages than entries in TLB.

ehh .. I've forgotten .. fcpu has SW TLB .. I spent too many
time with x86 thing ;-) Forget my note.
devik

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