Comment 7 for bug 1497428

Dan,

  I haven’t tried to directly reproduce the bug, but I have a few ideas. If I can free up some time I’ll see if I can reproduce it.

Dave Muysson | Cloud Architect
dave.muysson@360pi.com <mailto:dave.muysson@360pi.com> |​ (613) 562-2525 x 510 <tel:6135622525,510> |​ 360pi.com <http://360pi.com/>

> On Oct 13, 2015, at 9:20 AM, Dan Streetman <email address hidden> wrote:
>
> Hi Dave,
>
> are you able to reproduce the bug? The trace by itself isn't terribly helpful, all it really says is the pageblock spans zones, which means move_freepages_block() logic for detecting that failed for some reason. I have a debug kernel ppa here:
> pad.lv/ppa/ddstreet/lp1497428
>
> that includes additional debug if the problem happens (it also should
> prevent the BUG()). If you can use that kernel to trigger this and send
> the resulting debug output it would help very much :-)
>
> when the problem reproduces, in the system log you should see:
> page_zone(start_page) !=page_zone(end_page)
>
> and more debug following that. It should not trigger BUG() though, so
> you may need to check the logs periodically.
>
> Thanks!
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1497428
>
> Title:
> kernel BUG at /build/buildd/linux-3.13.0/mm/page_alloc.c:968
>
> Status in linux package in Ubuntu:
> In Progress
> Status in linux source package in Trusty:
> In Progress
>
> Bug description:
> The kernel triggers a BUG when it finds it is in move_freepages() but
> the start and end pfns for the move are in different zones.
>
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