Messages in this thread | | | Date | Mon, 15 Dec 2014 00:57:07 -0500 | From | Dave Jones <> | Subject | Re: frequent lockups in 3.18rc4 |
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On Sun, Dec 14, 2014 at 09:47:26PM -0800, Linus Torvalds wrote:
> so it's always in __do_page_fault, but at sometimes it has gotten into > handle_mm_fault too. So it really really looks like it is taking an > endless stream of page faults on that "xsaveq" instruction. Presumably > the page faulting never actually makes any progress, even though it > *thinks* the page tables are fine. > > DaveJ - you've seen that "endless page faults" behavior before. You > had a few traces that showed it. That was in that whole "pipe/page > fault oddness." email thread, where you would get endless faults in > copy_page_to_iter() with an error_code=0x2. > > That was the one where I chased it down to "page table entry must be > marked with _PAGE_PROTNONE", but VM_WRITE in the vma, because your > machine was alive enough that you got traces out of the endless loop.
We had a flashback to that old bug last month too. See this mail & your followup. : https://lkml.org/lkml/2014/11/25/1171 That was during a bisect though, so may have been something entirely different, but it is a spooky coincidence.
Dave
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