doc: add SST-BF info

In the Power Library, a new bit has been added to the mask returned by
rte_power_get_capabilities which indicates whether the core is an
Intel SST-BF high frequency core.

The distributor sample application has been enhanced to be aware of
Intel SST-BF high frequency cores. Docs also contain a link to
the Intel SST-BF application note.

Signed-off-by: David Hunt <david.hunt@intel.com>
Acked-by: John McNamara <john.mcnamara@intel.com>

diff --git a/doc/guides/rel_notes/release_19_05.rst b/doc/guides/rel_notes/release_19_05.rst
index 468e325..01a5555 100644 (file)
--- a/doc/guides/rel_notes/release_19_05.rst
+++ b/doc/guides/rel_notes/release_19_05.rst
@@ -200,6 +200,17 @@ New Features
   Improved testpmd application performance on ARM platform. For ``macswap``
   forwarding mode, NEON intrinsics were used to do swap to save CPU cycles.
 
+* **Updated power management library.**
+
+  Added support for Intel Speed Select Technology - Base Frequency (SST-BF).
+  ``rte_power_get_capabilities`` now has a bit in it's returned mask
+  indicating it's a high frequency core.
+
+* **Updated distributor sample application.**
+
+  Added support for Intel SST-BF feature so that the distributor core is
+  pinned to a high frequency core if available.
+
 
 Removed Items
 -------------

diff --git a/doc/guides/sample_app_ug/dist_app.rst b/doc/guides/sample_app_ug/dist_app.rst
index abfdd2c..90270e3 100644 (file)
--- a/doc/guides/sample_app_ug/dist_app.rst
+++ b/doc/guides/sample_app_ug/dist_app.rst
@@ -5,7 +5,9 @@ Distributor Sample Application
 ==============================
 
 The distributor sample application is a simple example of packet distribution
-to cores using the Data Plane Development Kit (DPDK).
+to cores using the Data Plane Development Kit (DPDK). It also makes use of
+Intel Speed Select Technology - Base Frequency (Intel SST-BF) to pin the
+distributor to the higher frequency core if available.
 
 Overview
 --------
@@ -101,6 +103,22 @@ final statistics to the user.
    Distributor Sample Application Layout
 
 
+Intel SST-BF Support
+--------------------
+
+In DPDK 19.05, support was added to the power management library for
+Intel-SST-BF, a technology that allows some cores to run at a higher
+frequency than others. An application note for Intel SST-BF is available,
+and is entitled
+`Intel Speed Select Technology – Base Frequency - Enhancing Performance <https://builders.intel.com/docs/networkbuilders/intel-speed-select-technology-base-frequency-enhancing-performance.pdf>`_
+
+The distributor application was also enhanced to be aware of these higher
+frequency SST-BF cores, and when starting the application, if high frequency
+SST-BF cores are present in the core mask, the application will identify these
+cores and pin the workloads appropriately. The distributor core is usually
+the bottleneck, so this is given first choice of the high frequency SST-BF
+cores, followed by the rx core and the tx core.
+
 Debug Logging Support
 ---------------------