Re: [RFC] mmap(MAP_CONTIG)

On Wed, 4 Oct 2017, Anshuman Khandual wrote:

quoted

- Using 'pre-allocated' pages in the fault paths may be intrusive.

But we have already faulted in all of them for the mapping and they
are also locked. Hence there should not be any page faults any more
for the VMA. Am I missing something here ?

The PTEs may be torn down and have to reestablished through a page faults.
Page faults would not allocate memory.

I am still wondering why wait till fault time not pre fault all of them
and populate the page tables.

They are populated but some processes (swap and migration) may tear them
down.