Hello Hugh, On Wed, Oct 21, 2015 at 05:59:59PM -0700, Hugh Dickins wrote: > On Thu, 22 Oct 2015, Minchan Kim wrote: > > > > I added the code to check it and queued it again but I had another oops > > in this time but symptom is related to anon_vma, too. > > (kernel is based on recent mmotm + unconditional mkdirty for bug fix) > > It seems page_get_anon_vma returns NULL since the page was not page_mapped > > at that time but second check of page_mapped right before try_to_unmap seems > > to be true. > > > > Adding 4191228k swap on /dev/vda5. Priority:-1 extents:1 across:4191228k FS > > Adding 4191228k swap on /dev/vda5. Priority:-1 extents:1 across:4191228k FS > > page:ffffea0001cfbfc0 count:3 mapcount:1 mapping:ffff88007f1b5f51 index:0x600000aff > > flags: 0x4000000000048019(locked|uptodate|dirty|swapcache|swapbacked) > > page dumped because: VM_BUG_ON_PAGE(PageAnon(page) && !PageKsm(page) && !anon_vma) > > That's interesting, that's one I added in my page migration series. > Let me think on it, but it could well relate to the one you got before. I will roll back to mm/madv_free-v4.3-rc5-mmotm-2015-10-15-15-20 instead of next-20151021 to remove noise from your migration cleanup series and will test it again. If it is fixed, I will test again with your migration patchset, then. > > > page->mem_cgroup:ffff88007f3dcc00 > > ------------[ cut here ]------------ > > kernel BUG at mm/migrate.c:889! > > invalid opcode: 0000 [#1] SMP > > Dumping ftrace buffer: > > (ftrace buffer empty) > > Modules linked in: > > CPU: 11 PID: 59 Comm: khugepaged Not tainted 4.3.0-rc6-next-20151021-THP-ref-madv_free+ #1557 > > Hmm, it might be me to blame, or it might be Kirill, don't know yet. It might be me, either. > > Oh, hold on, I think Andrew has just posted a new mmotm, and it includes > an update to Kirill's migrate_pages-try-to-split-pages-on-queueing.patch: > I haven't digested yet, but it might turn out to be relevant. > > Hugh -- 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>