Messages in this thread | | | Date | Mon, 16 Aug 2010 18:19:35 +0900 | From | Naoya Horiguchi <> | Subject | Re: [PATCH 0/9] Hugepage migration (v2) |
| |
On Fri, Aug 13, 2010 at 07:47:21AM -0500, Christoph Lameter wrote: > On Thu, 12 Aug 2010, Naoya Horiguchi wrote: > > > > Can you also avoid refcounts being increased during migration? > > > > Yes. I think this will be done in above-mentioned refactoring. > > Thats not what I meant. Can you avoid other processors increasing > refcounts (direct I/O etc?) on any page struct of the huge page while > migration is running?
In my understanding, in current code "other processors increasing refcount during migration" can happen both in non-hugepage direct I/O and in hugepage direct I/O in the similar way (i.e. get_user_pages_fast() from dio_refill_pages()). So I think there is no specific problem to hugepage. Or am I missing your point?
> > > This patch only handles migration under direct I/O. > > For the opposite (direct I/O under migration) it's not true. > > I wrote additional patches (later I'll reply to this email) > > for solving locking problem. Could you review them? > > Sure. > > > (Maybe these patches are beyond the scope of hugepage migration patch, > > so is it better to propose them separately?) > > Migration with known races is really not what we want in the kernel.
Yes.
Thanks, Naoya Horiguchi
| |