Re: kernel bug(VM_BUG_ON_PAGE) with 3.18.13 in mm/migrate.c

[Jovi Zhangwei <jovi@cloudflare.com>]

On Thu, May 28, 2015 at 11:38 AM, Jovi Zhangwei <jovi@cloudflare.com> wrote:
> Hi Mel,
>
> On Thu, May 28, 2015 at 5:00 AM, Mel Gorman <mgorman@suse.de> wrote:
>> On Wed, May 27, 2015 at 11:05:33AM -0700, Jovi Zhangwei wrote:
>>> Hi,
>>>
>>> I got below kernel bug error in our 3.18.13 stable kernel.
>>> "kernel BUG at mm/migrate.c:1661!"
>>>
>>> Source code:
>>>
>>> 1657    static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
>>> 1658   {
>>> 1659            int page_lru;
>>> 1660
>>> 1661           VM_BUG_ON_PAGE(compound_order(page) &&
>>> !PageTransHuge(page), page);
>>>
>>> It's easy to trigger the error by run tcpdump in our system.(not sure
>>> it will easily be reproduced in another system)
>>> "sudo tcpdump -i bond0.100 'tcp port 4242' -c 100000000000 -w 4242.pcap"
>>>
>>> Any comments for this bug would be great appreciated. thanks.
>>>
>>
>> What sort of compound page is it? What sort of VMA is it in? hugetlbfs
>> pages should never be tagged for NUMA migrate and never enter this
>> path. Transparent huge pages are handled properly so I'm wondering
>> exactly what type of compound page this is and what mapped it into
>> userspace.
>>
> Thanks for your reply.
>
> After reading net/packet/af_packet.c:alloc_one_pg_vec_page, I found
> there indeed have compound page maped into userspace.
>
> I sent a patch for this issue(you may received it), but not sure it's
> right to fix,
> feel free to update it or use your own patch.
>
ping?