RE: [RFC] Convert pgtable cache to slab

From: Luck, Tony <>
Date: 2004-10-14 05:07:17
>With this patch I got a significant improvement in page fault time.
>Standard 2.4.x was about 700ns on average.  Generic 2.6.9rc4 is 3-4
>usec, whereas the slabified pgtcache drops us back down to 600-700 ns.

What was the benchmark you were running when you measured these?

>Tested on zx1 and sn2.

How does this scale on big sn2 systems? I assume that the answers are
going to be just fine as the slab allocator per-cpu lists should be
just as nice as local quicklists, but it would be nice to see some

>The biggest caveat is that I've had to postpone setting up the gate
>page until the pgt slab has been initialized.  That wasn't an issue
>with the existing page-based allocation scheme.  David - how do you
>prefer I handle this?

I don't see the code for this postponement in this patch.


Overall looks nice ... less code, and goes faster too, what more
could we ask for!

Perhaps "zero_cache" isn't as descriptive a name as it might be (not
that I have any better suggestions :-(

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Received on Wed Oct 13 15:09:57 2004

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