Why unkillable process in RU state and spinning 100% on sys ?

Issue

We have un-killable process in RU state with following traces showing in the core :

PID: 16850  TASK: ffff881ab20eb8e0  CPU: 6   COMMAND: "python"
 #0 [ffff881fffa65e70] crash_nmi_callback at ffffffff81037882
 #1 [ffff881fffa65e80] nmi_handle at ffffffff815eb819
 #2 [ffff881fffa65ec8] do_nmi at ffffffff815eb930
 #3 [ffff881fffa65ef0] end_repeat_nmi at ffffffff815eac71
    [exception RIP: change_protection_range+1280]
    RIP: ffffffff81174450  RSP: ffff8819f03fbd68  RFLAGS: 00000282
    RAX: 0000000000000010  RBX: 0000000000000010  RCX: 0000000000000282
    RDX: ffff8819f03fbd68  RSI: 0000000000000018  RDI: 0000000000000001
    RBP: ffffffff81174450   R8: ffffffff81174450   R9: 0000000000000018
    R10: ffff8819f03fbd68  R11: 0000000000000282  R12: ffffffffffffffff
    R13: 800000242faa5166  R14: 00007feff7707000  R15: 800000242faa5166
    ORIG_RAX: 800000242faa5166  CS: 0010  SS: 0018
--- <DOUBLEFAULT exception stack> ---
 #4 [ffff8819f03fbd68] change_protection_range at ffffffff81174450
 #5 [ffff8819f03fbe68] change_protection at ffffffff81174795
 #6 [ffff8819f03fbea0] change_prot_numa at ffffffff8118a2eb
 #7 [ffff8819f03fbeb0] task_numa_work at ffffffff8109bc53
 #8 [ffff8819f03fbf00] task_work_run at ffffffff81082417
 #9 [ffff8819f03fbf30] do_notify_resume at ffffffff81012a77
#10 [ffff8819f03fbf50] retint_signal at ffffffff815ea6fc
    RIP: 00007ffff4b1895a  RSP: 00007fffffff5248  RFLAGS: 00000206
    RAX: 00007fa4491b9010  RBX: 00007fffffff53d0  RCX: 0000000000000000
    RDX: 00000002d014fba0  RSI: 00007fed23da5d30  RDI: 00007fad791e9d30
    RBP: 00007fffffff54d0   R8: 00007fa4491b9010   R9: 0000000000500000
    R10: 0000000000000008  R11: 00007ffff4a5343a  R12: 00007fffffff52d0
    R13: 0000000000000008  R14: 00000000006020a0  R15: 00007fffffff55d0
    ORIG_RAX: ffffffffffffffff  CS: 0033  SS: 002b