Kernel panic at down_read_trylock+0x9

Issue

• Server experiences kernel panic at down_read_trylock+0x9 after being called by page_lock_anon_vma_read:

    crash> bt
    PID: 926    TASK: ffff8820840c4500  CPU: 3   COMMAND: "java"
     #0 [ffff88245cdef5d8] machine_kexec at ffffffff81051e9b
     #1 [ffff88245cdef638] crash_kexec at ffffffff810f27e2
     #2 [ffff88245cdef708] oops_end at ffffffff8163f408
     #3 [ffff88245cdef730] die at ffffffff8101859b
     #4 [ffff88245cdef760] do_general_protection at ffffffff8163ecfe
     #5 [ffff88245cdef790] general_protection at ffffffff8163e5a8
        [exception RIP: down_read_trylock+0x9]                                  <--- panicked here and called from below
        RIP: ffffffff810aa9f9  RSP: ffff88245cdef848  RFLAGS: 00010282
        RAX: 0000000000000000  RBX: ffff883ec5bb5140  RCX: 0000000000000000
        RDX: 0000000000000000  RSI: 0000000000000000  RDI: ae275c445a85df8f
        RBP: ffff88245cdef848   R8: ffffea00528457a0   R9: ffff883fce384148
        R10: 0000000000000008  R11: 0000000000000002  R12: ffff883ec5bb5141
        R13: ffffea0052845780  R14: ae275c445a85df8f  R15: ffffea0052845780
        ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0000
     #6 [ffff88245cdef850] page_lock_anon_vma_read at ffffffff811a3335          <---
     #7 [ffff88245cdef880] page_referenced at ffffffff811a35b7
     #8 [ffff88245cdef8f8] shrink_active_list at ffffffff8117e8cc
     #9 [ffff88245cdef9b0] shrink_lruvec at ffffffff8117ef8d
    #10 [ffff88245cdefab0] shrink_zone at ffffffff8117f2a6
    #11 [ffff88245cdefb08] do_try_to_free_pages at ffffffff8117f7b0
    #12 [ffff88245cdefb80] try_to_free_pages at ffffffff8117fc9c
    #13 [ffff88245cdefc18] __alloc_pages_nodemask at ffffffff81173998
    #14 [ffff88245cdefd50] alloc_page_interleave at ffffffff811b480a
    #15 [ffff88245cdefd70] alloc_pages_vma at ffffffff811b8000
    #16 [ffff88245cdefdd8] do_huge_pmd_anonymous_page at ffffffff811cc973
    #17 [ffff88245cdefe38] handle_mm_fault at ffffffff8119714e
    #18 [ffff88245cdefec8] __do_page_fault at ffffffff81642000
    #19 [ffff88245cdeff28] do_page_fault at ffffffff81642323
    #20 [ffff88245cdeff50] page_fault at ffffffff8163e608
        RIP: 00007fb5c08d7c8b  RSP: 00007fb57dd7ab00  RFLAGS: 00010202
        RAX: 00007fb5c1226909  RBX: 00007fb5b9d7a800  RCX: 00007fb5c11f02b8
        RDX: 0000000000000002  RSI: 0000000756200800  RDI: 00007fb5b9d7a858
        RBP: 00007fb57dd7ab30   R8: 0000000000000002   R9: 0000000000000002
        R10: ffffffffffffffff  R11: 00007fb5c12eab4a  R12: 0000000756200800
        R13: 0000000000000003  R14: 00000007c00783f0  R15: 0000000000000020
        ORIG_RAX: ffffffffffffffff  CS: 0033  SS: 002b