Re: [Qemu-devel] [PATCH,RFC]: Generic memory callback regions

[Gianni Tedesco]

On Tue, 2004-06-01 at 06:13 -0500, Joe Batt wrote:
> I haven't read your patch, but I recently wrote a SH2 emulator.  We
> found that a lot of time was spent finding the right callbacks, so for
> the device memory, we used a sorted array.  After each access, we
> bubbled that memory region closed to the beginning of the array.  This
> turned out to be faster than the tree that we were using.  The main
> differences are we have 100+ regions and implemented it in Java.

Good call. Move-to-front heuristic seems smart because I anticipate (and
you found out for real) that memory accesses will have temporal
locality. Moving to head is theoretically the same or a little better
than 'bubbling up' actually, Knuth covers it in Vol 3 as i recall.

Well, it becomes irrelevent for this case now, as I am implementing this
privately in pciproxy.c, rather than publically in exec.c, and in my
case the list is always 1 item long :)

-- 
// Gianni Tedesco (gianni at scaramanga dot co dot uk)
lynx --source www.scaramanga.co.uk/scaramanga.asc | gpg --import
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