On Thu, 20 Feb 2003, Martin J. Bligh wrote:

quoted

Here's the fix we discussed for remap_page_range.  It sets the anon flag
for pages in any vma used for nonlinear.  It also requires that
MAP_NONLINEAR be passed in at mmap time to flag the vma.

Using the page based mechanism might also clear up some people's
concerns about small windows onto large shared areas for Oracle,
which will probably be using these nonlinear mappings anyway.

Good point.  Object based reverse mappings become unwieldy at about
the same point where the objects themselves get unwieldy.

A hybrid system with object based mappings in some cases and page
based mappings in other cases might work very nicely...

Yes, I'm sure there are other corner cases that need to be addressed
as well ;-)

There are, but at the moment I can't remember any as serious as the
"1000 tasks with 1000 small mappings of the same shared memory segment"
scenario.

This hybrid system looks like it is worth exploring.

regards,

Rik
-- 
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