On Wed, Apr 28, 2010 at 09:39:48AM +0900, KAMEZAWA Hiroyuki wrote: > Seems nice. What did you mean with objrmap inconsistency? I think this is single threaded there, userland didn't run yet and I don't think page faults could run. Maybe it's safer to add a VM_BUG_ON(vma->anon_vma) just before vma->anon_vma = anon_vma to be sure nothing run in between. > I'll test this but I think we need to take care of do_mremap(), too. > And it's more complicated.... do_mremap has to be safe by: 1) adjusting page->index atomically with the pte updates inside pt lock (while it moves from one pte to another) 2) having both vmas src and dst (not overlapping) indexed in the proper anon_vmas before move_page_table runs As long as it's not overlapping it shouldn't be difficult to enforce the above two invariants, exec.c is magic as it works on overlapping areas and src and dst are the same vma and it's indexed into just one anon-vma. So we've to stop the rmap_walks before we mangle over the vma with vma_adjust and move_page_tables and truncate the end of the vma with vma_adjust again, and finally we resume the rmap_walks. I'm not entirely sure of the above so review greatly appreciated ;) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>