Idle time in Oprofile

Hi,
In the context of my current activity witch intent to analyse Oprofile features, I would like to check if Oprofile is considering idle time in its profiling results. So for that purpose, I have run Oprofile without running any other application (the system is idle).  I used Oprofile in the timer mode.
First, I have run Oprofile on SH4 platform, and as following results show, 93% used by "poll_idle". 


15655    93.8437  vmlinux                  poll_idle
238       1.4267  vmlinux                  arch_local_irq_restore
28        0.1678  oprofiled                do_match
24        0.1439  oprofiled                pop_buffer_value
24        0.1439  vmlinux                  copy_page
18        0.1079  oprofiled                opd_process_samples
18        0.1079  oprofiled                sfile_find
16        0.0959  bash                     shell_getc
16        0.0959  libc-2.14.1.so           __gconv_transform_ascii_internal
16        0.0959  oprofiled                get_file
14        0.0839  libc-2.14.1.so           mbrtowc
14        0.0839  oprofiled                sfile_log_sample_count
13        0.0779  oprofiled                odb_update_node_with_offset
12        0.0719  libc-2.14.1.so           _int_malloc
9         0.0540  oprofiled                find_kernel_image
9         0.0540  vmlinux                  __copy_user
9         0.0540  vmlinux                  link_path_walk
9         0.0540  vmlinux                  nfs_permission
8         0.0480  ld-2.14.1.so             _dl_relocate_object
8         0.0480  vmlinux                  tcp_ack

I have also run Oprofile on ARM Cortex-a9 (SMP) whithout any application running (system is idle) and got 99.44% used by "fpa_get" function and there's nothing related to "idle".  

samples  %        app name                 symbol name
4148     99.4486  vmlinux                  fpa_get
2         0.0480  vmlinux                  print_cfs_rq
1         0.0240  bash                     hash_search
1         0.0240  bash                     parse_matched_pair
1         0.0240  gawk                     check_special
1         0.0240  ld-2.14.1.so             _dl_lookup_symbol_x
1         0.0240  libc-2.14.1.so           __default_morecore
1         0.0240  libc-2.14.1.so           __gconv_transform_ascii_internal
1         0.0240  libc-2.14.1.so           malloc_consolidate
1         0.0240  libc-2.14.1.so           strcpy
1         0.0240  vmlinux                  create_new_namespaces
1         0.0240  vmlinux                  dup_fd
1         0.0240  vmlinux                  fuse_copy_args
1         0.0240  vmlinux                  mnt_alloc_group_id
1         0.0240  vmlinux                  print_cpu
1         0.0240  vmlinux                  ptrace_request
1         0.0240  vmlinux                  seq_list_start_head
1         0.0240  vmlinux                  seq_write
1         0.0240  vmlinux                  usleep_range
1         0.0240  vmlinux                  vga_arbiter_notify_clients.part.11
1         0.0240  vmlinux                  vga_get
1         0.0240  vmlinux                  vm_insert_page
1         0.0240  vmlinux                  write_wb_reg

When searching in the official Oprofile documentation, I have found the following explanation
 " Your kernel is likely to support halting the processor when a CPU is idle. As the typical hardware events like CPU_CLK_UNHALTED do not count when the CPU is halted, the kernel profile will not reflect the actual amount of time spent idle.You can change this behaviour by booting with the idle=poll option, which uses a different idle routine. This will appear as poll_idle() in your kernel profile".
So I have rebooted my kernel with adding  idle=poll option, but I have not noticed any diffrence between the previous ones.

4707     99.5137  vmlinux                  fpa_get
2         0.0423  vmlinux                  attribute_container_unregister
2         0.0423  vmlinux                  print_cfs_rq
1         0.0211  bash                     execute_command_internal
1         0.0211  bash                     shell_getc
1         0.0211  libc-2.14.1.so           __gconv_transform_ascii_internal
1         0.0211  libc-2.14.1.so           sigprocmask
1         0.0211  libdl-2.14.1.so          call_gmon_start
1         0.0211  vmlinux                  __getnstimeofday
1         0.0211  vmlinux                  bdi_min_pause.isra.19
1         0.0211  vmlinux                  cgroup_scan_tasks
1         0.0211  vmlinux                  dev_alert
1         0.0211  vmlinux                  ext2_block_to_path.isra.19
1         0.0211  vmlinux                  ext4_ext_remove_space
1         0.0211  vmlinux                  iterate_supers
1         0.0211  vmlinux                  lg_local_lock
1         0.0211  vmlinux                  pipe_to_file
1         0.0211  vmlinux                  ptrace_request
1         0.0211  vmlinux                  register_filesystem
1         0.0211  vmlinux                  seq_write
1         0.0211  vmlinux                  sys_prctl
1         0.0211  vmlinux                  ubi_start_leb_change

Why does "idle_poll" does not appear in the "ARM" case? does it relate to architectural reasons?
Could we say that Oprofile is not intended to determine idle time ? or it's related to the configuration of the oprofile daemon?

BR

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