Re: big pages, base and bounds, Why I've Dropped In

According to Scott Lurndal <slp53@pacbell.net>:

(Yeah, I know some sysems have big pages and small pages but those
don't seem very popular. And some systems don't run I/O through a page
map so you have to coonsolidate space for large I/O operations.)

>
Large pages are problematic in that they must be naturally aligned
(i.e. a 4MB page must be aligned on a 4MB physical address boundary).

Indeed.

This makes it difficult to find sufficent aligned space for dynamic
allocation.  Initially, large pages were allocated at boot for use
by database applications.    Linux later developed transparent
huge pages (THP) which moved data around to create sufficiently
sized and aligned regions.

IBM 370 had 1MB secttions which could either be paged or one chunk,
to which z added 2GB regions, same thing.

IBM has invested a lot in z linux, should take a look and see what page
aanagement they offer.  2GB contiguous regions seem rather large, but on
a machine that can have 16TB of RAM, maybe not

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