On Fri, Mar 31, 2017 at 06:58:45PM +0100, Mark Rutland wrote: > Hi, > > I'm seeing intermittent bad page state splats on arm64 with 4.11-rc3 and > v4.11-rc4. I have not tested earlier kernels, or other architectures. > > So far, it looks like the flags are always bad in the same > way: > > bad because of flags: 0x80(waiters) > > ... though I don't know if that's definitely the case for splat 4, the > BUG at mm/page_alloc.c:800. > > I see this in QEMU VMs launched by Syzkaller, triggering once every few > hours. So far, I have not been able to reproduce the issue in any other > way (including using syz-repro). It looks like this may be an issue with the arm64 HUGETLB code. I wasn't able to trigger the issue over the weekend on a kernel with HUGETLBFS disabled. There are known issues with our handling of contiguous entries, and this might be an artefact of that. I'll see if I can narrow this down any further. Thanks, Mark. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
