On Sat, Dec 28, 2002 at 04:52:20PM -0800, Andrew Morton wrote:

quoted

wli-11_pgd_ctor.patch

On Wed, Jan 01, 2003 at 08:53:27PM -0800, William Lee Irwin III wrote:

A moment's reflection on the subject suggests to me it's worthwhile to
generalize pgd_ctor support so it works (without #ifdefs!) on both PAE
and non-PAE. This tiny tweak is actually more noticeably beneficial
on non-PAE systems but only really because pgd_alloc() is more visible;
the most likely reason it's less visible on PAE is "other overhead".
It looks particularly nice since it removes more code than it adds.
Touch tested on NUMA-Q (PAE). OFTC #kn testers testing the non-PAE case.

For those needing more interpretation, this is essentially a reinstatement
of the 2.4.x-style pgd/pmd cache optimization in a leak-free and accounted
(in /proc/slabinfo) manner.

The point of the optimizations is that these initializations are large
cache hits to take in a single shot, and in the PAE case, amount to a
full L1 cache flush as they traverse almost an entire 16K.

No rigorous benchmarking has been done yet.

Bill
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