Re: [RFC] i386: Remove page sized slabs for pgds and pmds

[Christoph Lameter <clameter@sgi.com>]

On Wed, 28 Mar 2007, William Lee Irwin III wrote:

> I'd also appreciate if it were mentioned who actually wrote this, given
> that the patch posted was what I sent you verbatim (and actually
> requested you not post for good reasons, some centering around pageattr.c).

Ughhh. Sorry I had this in there in early editions but removed the 
paragraph later.

> The salient point from the above, which was conveniently omitted, was
> "it's all dominated by PTE caching." However, even this needs some
> qualification having to do with the VSZ of the parent process in fork().
> For very small processes, such as cannot be constructed with glibc due
> to its massive bloat and cannot be constructed with the standard process
> address space layouts due to stacks being too distant from text and
> heap, PTE's actually don't substantially outnumber PMD's et al, so
> there is more to this story.

No that was described in the patch. Quote:

"i386 only provides support for caching constructed pgd and pmds. These 
are comparatively rare to ptes so it is no surprise that the current 
approach has only minimal effect. ...."