On Tue, Oct 8, 2013 at 11:36 AM, Peter Zijlstra <pet...@infradead.org> wrote: > On Tue, Oct 08, 2013 at 09:15:30AM +0200, Stephane Eranian wrote: >> Yes, it is but I am trying to see whether or not we could unify that and >> use a single u64 number to uniquely identify each mapping. > > No you cannot; two unrelated executables which have distinct mm_ids can > easily mmap() the same shared file.
That seems to indicate the mm_ids is not attached to the right level of VM data structure. But I am okay with keeping it that way and stashing the mm_id as a pseudo inode number for the case of non file-backed mappings. If we say maj=min=ino=gen=0 means no "info", then any other combinations can be used to identify identical mappings. We use actual min,maj, ino, gen for file backed, and maj=min=gen=0 + ino = mm_ids for the other cases. That should work, shouldn't it? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
