On Tue, Oct 15, 2013 at 08:55:10PM +0200, Andrea Arcangeli wrote: > On Tue, Oct 15, 2013 at 10:53:10AM -0700, Hugh Dickins wrote: > > I'm afraid Andrea's mail about concurrent madvises gives me far more > > to think about than I have time for: seems to get into problems he > > knows a lot about but I'm unfamiliar with. If this patch looks good > > for now on its own, let's put it in; but no problem if you guys prefer > > to wait for a fuller solution of more problems, we can ride with this > > one internally for the moment. > > I'm very happy with the patch and I think it's a correct fix for the > COW scenario which is deterministic so the looping makes a meaningful > difference for it. If we wouldn't loop, part of the copied page > wouldn't be zapped after the COW.
I like this patch, too. If we have the loop in __split_huge_page_pmd as suggested in this patch, can we assume that the pmd is stable after __split_huge_page_pmd returns? If it's true, we can remove pmd_none_or_trans_huge_or_clear_bad check in the callers side (zap_pmd_range and some other page table walking code.) Naoya Horiguchi -- 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/
