Re: [PATCH RFC] mm/madvise: introduce MADV_POPULATE to prefault/prealloc memory

[Rolf Eike Beer]

> > Let's introduce MADV_POPULATE with the following semantics
> > 1. MADV_POPULATED does not work on PROT_NONE and special VMAs. It 
> > works
> >    on everything else.
> > 2. Errors during MADV_POPULATED (especially OOM) are reported. If we 
> > hit
> >    hardware errors on pages, ignore them - nothing we really can or
> >    should do.
> > 3. On errors during MADV_POPULATED, some memory might have been
> >    populated. Callers have to clean up if they care.
> > 4. Concurrent changes to the virtual memory layour are tolerated - we
                                                    ^t
> >    process each and every PFN only once, though.
> > 5. If MADV_POPULATE succeeds, all memory in the range can be accessed
> >    without SIGBUS. (of course, not if user space changed mappings in 
> > the
> >    meantime or KSM kicked in on anonymous memory).

You are talking both about MADV_POPULATE and MADV_POPULATED here.

Eike