On Tue, May 12, 2015 at 03:28:40PM -0700, Andrew Morton wrote: > Please let's not put things like WRITE_ONCE() in there without > documenting them - otherwise it's terribly hard for readers to work out > why it was added. > > How's this look? > > --- > a/mm/rmap.c~rmap-fix-theoretical-race-between-do_wp_page-and-shrink_active_list-fix > +++ a/mm/rmap.c > @@ -950,6 +950,11 @@ void page_move_anon_rmap(struct page *pa > VM_BUG_ON_PAGE(page->index != linear_page_index(vma, address), page); > > anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON; > + /* > + * Ensure that anon_vma and the PAGE_MAPPING_ANON bit are written > + * simultaneously, so a concurrent reader (eg shrink_active_list) will > + * not see one without the other. > + */ > WRITE_ONCE(page->mapping, (struct address_space *) anon_vma); > }
Looks good to me. Thanks, Vladimir -- 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/
