[dpdk-dev] [PATCH] doc: add how to enable empty cycles profiling

[dpdk-dev] [PATCH] doc: add how to enable empty cycles profiling

[ilia.kurakin]

From: Ilia Kurakin <ilia.kurakin@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.kurakin@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


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Re: [dpdk-dev] [PATCH] doc: add how to enable empty cycles profiling

[Mcnamara, John]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of
> ilia.kurakin@intel.com
> Sent: Monday, July 24, 2017 6:24 PM
> To: dev@dpdk.org
> Cc: jerin.jacob@caviumnetworks.com; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; Wiles, Keith <keith.wiles@intel.com>;
> Galanov, Dmitry <dmitry.galanov@intel.com>; Kurakin, Ilia
> <ilia.kurakin@intel.com>
> Subject: [dpdk-dev] [PATCH] doc: add how to enable empty cycles profiling
> 
> From: Ilia Kurakin <ilia.kurakin@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/

Hi Ilia,

Thanks for the doc patch.


> 
> +Profiling wasted iterations with ITT
> +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Probably better to call this VTune ITT


> +
> +Iterations that yielded no RX packets (wasted loop iterations) can be
> +analyzed using Intel® VTune\ :sup:`TM` Amplifier. 

You don't need a superscript here. You can use the TM symbol directly like
the previous (R) symbol.

> 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.

For future patches you should omit this footer. I'll send you some instructions
on how to do that.

John

Re: [dpdk-dev] [PATCH] doc: add how to enable empty cycles profiling

[Mcnamara, John]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Mcnamara, John
> Sent: Tuesday, July 25, 2017 11:05 AM
> To: Kurakin, Ilia <ilia.kurakin@intel.com>; dev@dpdk.org
> Cc: jerin.jacob@caviumnetworks.com; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; Wiles, Keith <keith.wiles@intel.com>;
> Galanov, Dmitry <dmitry.galanov@intel.com>; Kurakin, Ilia
> <ilia.kurakin@intel.com>
> Subject: Re: [dpdk-dev] [PATCH] doc: add how to enable empty cycles
> profiling
> 
> 
> 
> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of
> > ilia.kurakin@intel.com
> > Sent: Monday, July 24, 2017 6:24 PM
> > To: dev@dpdk.org
> > Cc: jerin.jacob@caviumnetworks.com; Ananyev, Konstantin
> > <konstantin.ananyev@intel.com>; Wiles, Keith <keith.wiles@intel.com>;
> > Galanov, Dmitry <dmitry.galanov@intel.com>; Kurakin, Ilia
> > <ilia.kurakin@intel.com>
> > Subject: [dpdk-dev] [PATCH] doc: add how to enable empty cycles
> > profiling
> >
> > From: Ilia Kurakin <ilia.kurakin@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/
> 
> Hi Ilia,
> 
> Thanks for the doc patch.
> 
> 
> >
> > +Profiling wasted iterations with ITT
> > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Probably better to call this VTune ITT
> 
> 
> > +
> > +Iterations that yielded no RX packets (wasted loop iterations) can be
> > +analyzed using Intel® VTune\ :sup:`TM` Amplifier.
> 
> You don't need a superscript here. You can use the TM symbol directly like
> the previous (R) symbol.
> 

P.S., it might to better to move the (R) and (TM) to the previous paragraph
where Vtune is used for the first time.

John

[dpdk-dev] [PATCH v2] doc: add how to enable empty cycles profiling

[ilia.kurakin]

From: Ilia Kurakin <ilia.kurakin@intel.com>

Programmers 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.kurakin@intel.com>

---

-V2 change:
    Fixes due to review


 doc/guides/prog_guide/profile_app.rst | 37 ++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/doc/guides/prog_guide/profile_app.rst b/doc/guides/prog_guide/profile_app.rst
index 54b546a..f1d6eeb 100644
--- a/doc/guides/prog_guide/profile_app.rst
+++ b/doc/guides/prog_guide/profile_app.rst
@@ -39,7 +39,8 @@ Profiling on x86
 ----------------
 
 Intel processors provide performance counters to monitor events.
-Some tools provided by Intel, such as VTune, can be used to profile and benchmark an application.
+Some tools provided by Intel, such as Intel® VTune™ Amplifier, can be used
+to profile and benchmark an application.
 See the *VTune Performance Analyzer Essentials* publication from Intel Press for more information.
 
 For a DPDK application, this can be done in a Linux* application environment only.
@@ -59,6 +60,40 @@ Refer to the
 for details about application profiling.
 
 
+VTune ITT
+~~~~~~~~~
+
+Iterations that yielded no RX packets (wasted loop iterations) can be analyzed
+using VTune 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
 ------------------
 
-- 
2.9.3

Re: [dpdk-dev] [PATCH v2] doc: add how to enable empty cycles profiling

[Mcnamara, John]

> -----Original Message-----
> From: Kurakin, Ilia
> Sent: Wednesday, July 26, 2017 4:20 PM
> To: dev@dpdk.org
> Cc: jerin.jacob@caviumnetworks.com; Mcnamara, John
> <john.mcnamara@intel.com>; Galanov, Dmitry <dmitry.galanov@intel.com>;
> Kurakin, Ilia <ilia.kurakin@intel.com>
> Subject: [PATCH v2] doc: add how to enable empty cycles profiling
> 
> From: Ilia Kurakin <ilia.kurakin@intel.com>
> 
> Programmers 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.kurakin@intel.com>

Acked-by: John McNamara <john.mcnamara@intel.com>