[dpdk-users] [ovs-dev] OVS with DPDK Meetup notes

[Panu Matilainen]

On 11/26/2015 07:56 PM, Traynor, Kevin wrote:
> Hi All,
>
> Just wanted to post some summary notes on the recent OVS with DPDK Meetup we
> had after the OVS conference. Thanks to everyone for the often lively discussion.
> I've collated and condensed Maryam's notes (Thank you Maryam) with my own.
> Corrections and additions are welcome.
>
> Usability
> ==========
> * Command line options
>    - Create defaults which can be overridden on the command line.
>    -c 0x1
>    -n 4 (this will be in DPDK 2.2 also)
>    -socket-mem 1024,0

Another possibility might be saving these in Open_vSwitch other_config 
db along with pmd-cpu-mask and the like. DPDK init could be delayed 
until the config db is available I think.

OTOH the command line variant is perhaps less effort. I've been carrying 
the following patch in my packages to allow passing arbitrary DPDK 
options to OVS service start via DPDK_OPTIONS in 
/etc/sysconfig/openvswitch,:

diff --git a/utilities/ovs-ctl.in b/utilities/ovs-ctl.in
index 6d2e938..7db1500 100755
--- a/utilities/ovs-ctl.in
+++ b/utilities/ovs-ctl.in
@@ -240,8 +240,11 @@ start_forwarding () {
          fi

             # Start ovs-vswitchd.
-           set ovs-vswitchd unix:"$DB_SOCK"
-           set "$@" -vconsole:emer -vsyslog:err -vfile:info
+           set ovs-vswitchd
+           if test X"$DPDK_OPTIONS" != X; then
+               set "$@" --dpdk $DPDK_OPTIONS --
+           fi
+           set "$@" unix:"$DB_SOCK" -vconsole:emer -vsyslog:err -vfile:info
             if test X"$MLOCKALL" != Xno; then
                 set "$@" --mlockall
             fi

With that, the truly trivial (if a bit cheap) way of adding workable 
defaults becomes basically just:

diff --git 
a/rhel/usr_share_openvswitch_scripts_systemd_sysconfig.template 
b/rhel/usr_share_openvswitch_scripts_systemd_sysconfig.template
index 3050a07..d5bfe9d 100644
--- a/rhel/usr_share_openvswitch_scripts_systemd_sysconfig.template
+++ b/rhel/usr_share_openvswitch_scripts_systemd_sysconfig.template
@@ -21,3 +21,6 @@
  #   --ovsdb-server-wrapper=valgrind
  #
  OPTIONS=""
+
+# Uncomment to enable DPDK
+#DPDK_OPTIONS="-c0x1 -n4 --socket-mem 1024,0"


	- Panu -