On Thu, 26 Jul 2007, Roland McGrath wrote: > > > hm, I'm now wondering whether testing i_nlink was the best (or official) > > way of determining whether a MAP_SHARED vma is anonymous or file-backed. > > Hugh will know. > > Well, it doesn't exactly test that it's not "file-backed". (Technically > anything shared is file-backed, even if by a shmem virtual file.) It tests > whether the backing file will probably ever be found on disk later. That > gets shmem regions as well as originally-regular files that were deleted > while mapped. I think we asked around when this test was put it and it was > deemed proper at the time. (It doesn't really need to be a formal "what > does the vm situation mean" guarantee, just a practical "you probably > wanted that" test.)
Exactly, a rough heuristic which seemed to approximate what the coredump people wanted when it went into 2.6.12. No absolute justification to it. Hugh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
