From: Ilia Kurakin <ilia.kura...@intel.com> Programmer's Guide: section "Profile Your Application" updated with how to enable ITT tasks collection. Based on patch: http://dpdk.org/dev/patchwork/patch/27158/
Signed-off-by: Ilia Kurakin <ilia.kura...@intel.com> --- doc/guides/prog_guide/profile_app.rst | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/doc/guides/prog_guide/profile_app.rst b/doc/guides/prog_guide/profile_app.rst index 54b546a..a52fd70 100644 --- a/doc/guides/prog_guide/profile_app.rst +++ b/doc/guides/prog_guide/profile_app.rst @@ -59,6 +59,40 @@ Refer to the for details about application profiling. +Profiling wasted iterations with ITT +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Iterations that yielded no RX packets (wasted loop iterations) can be analyzed +using Intel® VTune\ :sup:`TM` Amplifier. This profiling employs the +`Instrumentation and Tracing Technology (ITT) API +<https://software.intel.com/en-us/node/544195>`_ +feature of VTune Amplifier and requires only reconfiguring the DPDK library, +no changes in a DPDK application are needed. + +To trace wasted iterations on RX queues, first reconfigure DPDK with +``CONFIG_RTE_ETHDEV_RXTX_CALLBACKS`` and +``CONFIG_RTE_ETHDEV_PROFILE_ITT_WASTED_RX_ITERATIONS`` enabled. + +Then rebuild DPDK, specifying paths to the ITT header and library, which can +be found in any VTune Amplifier distribution in the *include* and *lib* +directories respectively: + +.. code-block:: console + + make EXTRA_CFLAGS=-I<path to ittnotify.h> \ + EXTRA_LDLIBS="-L<path to libittnotify.a> -littnotify" + +Finally, to see wasted iterations in your performance analysis results, +select the *"Analyze user tasks, events, and counters"* checkbox in the +*"Analysis Type"* tab when configuring analysis via VTune Amplifier GUI. +Alternatively, when running VTune Amplifier via command line, specify +``-knob enable-user-tasks=true`` option. + +Collected regions of wasted iterations will be marked on VTune Amplifier's +timeline as ITT tasks. These ITT tasks have predefined names, containing +Ethernet device and RX queue identifiers. + + Profiling on ARM64 ------------------ -- 2.7.4 -------------------------------------------------------------------- Joint Stock Company Intel A/O Registered legal address: Krylatsky Hills Business Park, 17 Krylatskaya Str., Bldg 4, Moscow 121614, Russian Federation This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies.
