<div dir="ltr"><div>Hello all,<br><br></div><div>I am running the Iozone benchmark commands to find disk characteristics on my system and <br>trying to construct a call graph for the iozone functions.<br></div><div>I am using perf tools to generate a call graph , but I am having trouble understanding the output from the perf commands as follows--<br>

<br><br># Events: 62K cpu-clock<br>#<br># Overhead         Command               Shared Object                                                                                                                          Symbol<br>

# ........  ..............  ..........................  ..............................................................................................................................<br>#<br>    79.23%         swapper  [kernel.kallsyms]           [k] native_safe_halt<br>

                   |<br>                   --- native_safe_halt<br>                       default_idle<br>                       cpu_idle<br>                       start_kernel<br>                       x86_64_start_kernel<br>

<br>     4.99%          iozone  [kernel.kallsyms]           [k] copy_user_generic_unrolled<br>                    |<br>                    --- copy_user_generic_unrolled<br>                        iov_iter_copy_from_user_atomic<br>

                        generic_perform_write<br>                        generic_file_buffered_write<br>                        __generic_file_aio_write<br>                        generic_file_aio_write<br>                        ext4_file_write<br>

                        do_sync_write<br>                        vfs_write<br>                        sys_write<br>                        ia32_sysret    <br>                        0xf77904be<br>                        __write_nocancel<br>

<br></div><div><br></div><div>I need to understand these kernel commands , kindly give some pointers for the same. Are there any resources available online ??<br></div><div>I am attaching the complete file along with the mail.<br>

</div><div><br></div><div><br>Thanks and regards,<br><br><b>Nitisha</b><br>
</div></div>