Re: Variability in cache access times

Linus Torvalds (torvalds@transmeta.com)
28 Jan 1999 18:55:15 GMT


In article <199901281631.QAA03159@dax.scot.redhat.com>,
Stephen C. Tweedie <sct@redhat.com> wrote:
>
>As far as the Intel CPU is concerned, it is not particularly hard. The
>real problem as far as Linux itself is concerned is twofold: first, it
>requires contiguous 4MB pages, and secondly Linux assumes a uniform,
>fixed-depth page table hierarchy.

Actually, the latter I already did at one point (it worked well - I made
sure that the page mapping functions worked in kernel space too, even
though all 1:1-mapped kernel pages used 4M addressing).

I removed this simply because there wasn't enough use for it, and it
complicated the code slightly (not much, but considering that nobody
used it it wasn't worth maintaining).

Linus

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