On Wed, Jul 22, 2015 at 10:32:20AM -0400, Eric B Munson wrote: > On Wed, 22 Jul 2015, Kirill A. Shutemov wrote: > > > On Tue, Jul 21, 2015 at 03:59:40PM -0400, Eric B Munson wrote: > > > The cost of faulting in all memory to be locked can be very high when > > > working with large mappings. If only portions of the mapping will be > > > used this can incur a high penalty for locking. > > > > > > Now that we have the new VMA flag for the locked but not present state, > > > expose it as an mmap option like MAP_LOCKED -> VM_LOCKED. > > > > What is advantage over mmap() + mlock(MLOCK_ONFAULT)? > > There isn't one, it was added to maintain parity with the > mlock(MLOCK_LOCK) -> mmap(MAP_LOCKED) set. I think not having will lead > to confusion because we have MAP_LOCKED so why don't we support > LOCKONFAULT from mmap as well. I don't think it's ia good idea to spend bits in flags unless we have a reason for that. BTW, you have typo on sparc: s/0x8000/0x80000/. -- Kirill A. Shutemov
