`perf top` output on 4.15.0-20-generic 

13,09%  [kernel]                        [k] acpi_os_read_port
11,81%  [kernel]                        [k] acpi_ns_search_one_scope
 6,42%  [kernel]                        [k] acpi_os_write_port
 4,62%  [kernel]                        [k] acpi_ut_track_stack_ptr
 4,17%  [kernel]                        [k] acpi_ut_trace_ptr
 3,42%  [kernel]                        [k] strncpy
 3,28%  [kernel]                        [k] __tick_nohz_idle_enter
 2,49%  [kernel]                        [k] acpi_ut_status_exit
 1,63%  [kernel]                        [k] acpi_ex_resolve_node_to_value
 1,50%  [kernel]                        [k] nmi
 1,34%  libapt-pkg.so.5.0.2             [.] lroundf@plt
 1,31%  [kernel]                        [k] acpi_ut_update_ref_count.part.1
 1,28%  [kernel]                        [k] acpi_ex_resolve_operands
 1,25%  [kernel]                        [k] acpi_ut_add_reference
 1,23%  [kernel]                        [k] acpi_ut_acquire_mutex
 1,19%  libapt-pkg.so.5.0.2             [.] _ZNK8pkgCache11DepIterator10IsNegativeEv
 1,18%  [kernel]                        [k] acpi_ns_evaluate
 1,12%  [kernel]                        [k] acpi_ut_trace
 1,00%  libstdc++.so.6.0.25             [.] _ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE9_M_createERmm
 0,97%  [kernel]                        [k] _find_next_bit
 0,92%  [kernel]                        [k] kmem_cache_alloc
 0,82%  [kernel]                        [k] rcu_note_context_switch
 0,71%  [kernel]                        [k] menu_select
 0,67%  [kernel]                        [k] __kmalloc
 0,64%  [kernel]                        [k] acpi_ut_valid_internal_object
 0,62%  [kernel]                        [k] acpi_ut_update_object_reference
 0,57%  [kernel]                        [k] kfree
 0,57%  libapt-pkg.so.5.0.2             [.] _Z13stringcasecmpN9__gnu_cxx17__normal_iteratorIPKcNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEES9_S2_S2_
 0,51%  libapt-pkg.so.5.0.2             [.] _ZN6FileFd5WriteEPKvy
 0,49%  [kernel]                        [k] kmem_cache_free
 0,48%  [kernel]                        [k] acpi_ns_lookup
 0,48%  python3.6                       [.] 0x0000000000184852
 0,47%  [kernel]                        [k] acpi_hw_validate_io_request
 0,45%  [kernel]                        [k] acpi_ut_match_predefined_method
 0,42%  [kernel]                        [k] prefetch_freepointer
 0,39%  [kernel]                        [k] acpi_ps_get_next_arg
 0,39%  [kernel]                        [k] acpi_ut_get_next_predefined_method
 0,35%  [kernel]                        [k] acpi_ds_exec_begin_op
 0,35%  [kernel]                        [k] acpi_ps_create_op
 0,33%  [kernel]                        [k] acpi_ps_get_opcode_info
 0,33%  [kernel]                        [k] acpi_ps_parse_loop
 0,32%  [kernel]                        [k] acpi_ut_repair_name
 0,31%  [kernel]                        [k] acpi_ex_read_data_from_field
 0,31%  [kernel]                        [k] acpi_ns_build_normalized_path
 0,30%  [kernel]                        [k] acpi_ds_delete_result_if_not_used
 0,30%  [kernel]                        [k] acpi_ds_create_operand
 0,28%  [kernel]                        [k] acpi_ds_exec_end_op
 0,28%  [kernel]                        [k] __schedule
 0,27%  [kernel]                        [k] acpi_ds_evaluate_name_path
 0,26%  libc-2.27.so                    [.] __GI___strlen_sse2
 0,26%  [kernel]                        [k] acpi_ex_name_segment
 0,25%  [kernel]                        [k] memset_erms
 0,25%  python3.6                       [.] 0x00000000000436c0
 0,24%  [kernel]                        [k] acpi_ns_search_and_enter
 0,24%  python3.6                       [.] 0x0000000000043710