dpif-netdev: Add packet count and core id paramters for study

This commit introduces additional command line paramter
for mfex study function. If user provides additional packet out
it is used in study to compare minimum packets which must be processed
else a default value is choosen.
Also introduces a third paramter for choosing a particular pmd core.

$ ovs-appctl dpif-netdev/miniflow-parser-set study 500 3

Signed-off-by: Kumar Amber <kumar.amber@intel.com>
Acked-by: Flavio Leitner <fbl@sysclose.org>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Ian Stokes <ian.stokes@intel.com>

1 files changed, 36 insertions, 2 deletions

diff --git a/Documentation/topics/dpdk/bridge.rst b/Documentation/topics/dpdk/bridge.rst
index a47153495..8c500c504 100644
--- a/Documentation/topics/dpdk/bridge.rst
+++ b/Documentation/topics/dpdk/bridge.rst
@@ -284,12 +284,46 @@ command also shows whether the CPU supports each implementation ::
 
 An implementation can be selected manually by the following command ::
 
-    $ ovs-appctl dpif-netdev/miniflow-parser-set study
+    $ ovs-appctl dpif-netdev/miniflow-parser-set [-pmd core_id] [name]
+                                                 [study_cnt]
+
+The above command has two optional parameters: study_cnt and core_id.
+The core_id sets a particular miniflow extract function to a specific
+pmd thread on the core. The third parameter study_cnt, which is specific
+to study and ignored by other implementations, means how many packets
+are needed to choose the best implementation.
 
 Also user can select the study implementation which studies the traffic for
 a specific number of packets by applying all available implementations of
 miniflow extract and then chooses the one with the most optimal result for
-that traffic pattern.
+that traffic pattern. The user can optionally provide an packet count
+[study_cnt] parameter which is the minimum number of packets that OVS must
+study before choosing an optimal implementation. If no packet count is
+provided, then the default value, 128 is chosen. Also, as there is no
+synchronization point between threads, one PMD thread might still be running
+a previous round, and can now decide on earlier data.
+
+The per packet count is a global value, and parallel study executions with
+differing packet counts will use the most recent count value provided by user.
+
+Study can be selected with packet count by the following command ::
+
+    $ ovs-appctl dpif-netdev/miniflow-parser-set study 1024
+
+Study can be selected with packet count and explicit PMD selection
+by the following command ::
+
+    $ ovs-appctl dpif-netdev/miniflow-parser-set -pmd 3 study 1024
+
+In the above command the first parameter is the CORE ID of the PMD
+thread and this can also be used to explicitly set the miniflow
+extraction function pointer on different PMD threads.
+
+Scalar can be selected on core 3 by the following command where
+study count should not be provided for any implementation other
+than study ::
+
+    $ ovs-appctl dpif-netdev/miniflow-parser-set -pmd 3 scalar
 
 Miniflow Extract Validation
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~