Messages in this thread | | | Date | Mon, 14 Nov 2005 14:41:11 +0200 | From | Gleb Natapov <> | Subject | Re: Nick's core remove PageReserved broke vmware... |
| |
On Mon, Nov 14, 2005 at 02:34:32PM +0200, Michael S. Tsirkin wrote: > Quoting Gleb Natapov <gleb@minantech.com>: > > Subject: Re: Nick's core remove PageReserved broke vmware... > > > > On Mon, Nov 14, 2005 at 02:25:35PM +0200, Michael S. Tsirkin wrote: > > > Quoting Hugh Dickins <hugh@veritas.com>: > > > > Subject: Re: Nick's core remove PageReserved broke vmware... > > > > > > > > On Tue, 8 Nov 2005, Michael S. Tsirkin wrote: > > > > > > > > > > Hugh, did you have something like the following in mind > > > > > (this is only boot-tested and only on x86-64)? > > > > > > > > Yes, that looks pretty good to me, a few comments below. > > > > Only another twenty or so architectures to go ;) > > > > > > There's one thing that I have thought about: what happens > > > if I set DONTFORK on a page which already has COW set > > > (e.g. after fork)? > > > > > > It seems that the right thing would be to force a page copy - > > > otherwise the page can get copied on write. > > > > I thought about it. It should not happen for OpenIB since get_user_pages > > will break COW for us and I don't think we should complicate DONTFORK > > implementation by doing break during madvise(). > > Hmm, I assumed we call madvise before driver does get_user_pages, > otherwise an application could fork in between. > Should we worry about this? > OK, we set VM_DONTFORK on vma and than driver calls get_user_pages() that actually do page table walking and COW breaking. Or do I miss something here?
-- Gleb. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |