Messages in this thread | | | Date | Thu, 4 Jun 2009 15:02:55 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH] [6/16] HWPOISON: Add various poison checks in mm/memory.c |
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On Thu, Jun 04, 2009 at 08:50:26PM +0800, Wu Fengguang wrote: > On Thu, Jun 04, 2009 at 08:52:28PM +0800, Andi Kleen wrote: > > On Thu, Jun 04, 2009 at 07:55:33PM +0800, Wu Fengguang wrote: > > > On Thu, Jun 04, 2009 at 01:19:15PM +0800, Andi Kleen wrote: > > > > On Thu, Jun 04, 2009 at 12:26:03PM +0800, Wu Fengguang wrote: > > > > > On Thu, Jun 04, 2009 at 02:46:38AM +0800, Andi Kleen wrote: > > > > > > > > > > > > Bail out early when hardware poisoned pages are found in page fault handling. > > > > > > > > > > I suspect this patch is also not absolutely necessary: the poisoned > > > > > page will normally have been isolated already. > > > > > > > > It's needed to prevent new pages comming in when there is a parallel > > > > fault while the memory failure handling is in process. > > > > Otherwise the pages could get remapped in that small window. > > > > > > This patch makes no difference at least for file pages, including tmpfs. > > > > I was more thinking of anonymous pages with multiple mappers (e.g. > > COW after fork) > > I guess they are handled by do_anonymous_page() or do_wp_page(), > instead of do_linear_fault()/do_nonlinear_fault()?
You're right. Sorry was a little confused in my earlier reply.
I think what I meant is: what happens during the window when the page has just the poison bit set, but is not isolated/unmapped yet. During that window I want new mappers to not come in. That is why that check is there.
-Andi
-- ak@linux.intel.com -- Speaking for myself only.
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