Hi,
Benno Senoner writes:
> Yes, I run with mlockall(MCL_CURRENT|MCL_FUTURE)
> I can confirm this now:
> I just removed my memcpy()s for testing purposes, and the app loads the
> data nicely.
As it should be. mlock/mlockall apply to _all_ pages which appear in
your process' address space, regardless of whether they are page cache
or local data pages.
> Pratically this means that if you enabled MCL_FUTURE, mmap() will
> return only after all the mapped segment of the file resides in
> memory. Correct me please if I am wrong.
Yes. If MCL_FUTURE is used then all future mmap()s are automatically
marked as locked, and we do a make_pages_present() before returning
from mmap. This is exactly what mlockall is designed for: memory
access should simply never page fault if you use MCL_CURRENT |
MCL_FUTURE. This is even true for writable MAP_PRIVATE pages: if you
have full mlockall enabled, then the make_pages_present() will do a
copy-on-write page fault for you.
--Stephen
