On Tue, 2 Apr 2013, Jan Stancek wrote: > find_vma() can be called by multiple threads with read lock > held on mm->mmap_sem and any of them can update mm->mmap_cache. > Prevent compiler from re-fetching mm->mmap_cache, because other > readers could update it in the meantime: > FWIW, ACCESS_ONCE() does not guarantee that the compiler will not refetch mm->mmap_cache whatsoever; there is nothing that prevents this either in the C standard. You'll be relying solely on gcc's implementation of how it dereferences volatile-qualified pointers. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>