report 1904: updated methodology (nfv density, startup.conf) and vpp perf rls notes

Change-Id: If6d24511d5d29dcc25c21437364e0da15af3cca1
Signed-off-by: Maciek Konstantynowicz <mkonstan@cisco.com>

1 files changed, 17 insertions, 14 deletions

diff --git a/docs/report/introduction/methodology_vpp_startup_settings.rst b/docs/report/introduction/methodology_vpp_startup_settings.rst
index 81c5e4e73e..e3e8d29b23 100644
--- a/docs/report/introduction/methodology_vpp_startup_settings.rst
+++ b/docs/report/introduction/methodology_vpp_startup_settings.rst
@@ -1,29 +1,32 @@
 VPP Startup Settings
 --------------------
 
-CSIT code manipulates a number of VPP settings in startup.conf for optimized
-performance. List of common settings applied to all tests and test
-dependent settings follows.
+CSIT code manipulates a number of VPP settings in startup.conf for
+optimized performance. List of common settings applied to all tests and
+test dependent settings follows.
 
-See `VPP startup.conf`_
-for a complete set and description of listed settings.
+See `VPP startup.conf`_ for a complete set and description of listed
+settings.
 
 Common Settings
 ~~~~~~~~~~~~~~~
 
-List of vpp startup.conf settings applied to all tests:
+List of VPP startup.conf settings applied to all tests:
 
 #. heap-size <value> - set separately for ip4, ip6, stats, main
    depending on scale tested.
-#. no-tx-checksum-offload - disables UDP / TCP TX checksum offload in DPDK.
-   Typically needed for use faster vector PMDs (together with
+#. no-tx-checksum-offload - disables UDP / TCP TX checksum offload in
+   DPDK. Typically needed for use faster vector PMDs (together with
    no-multi-seg).
-#. buffers-per-numa <value> - increases number of buffers allocated, needed
-   in scenarios with large number of interfaces and worker threads.
-   Value is per CPU socket. Default is 16384. CSIT is setting statically
-   107520 buffers per CPU thread (215040 if HTT is enabled). This value is also
-   maximum possible amount limited by number of memory mappings in DPDK
-   libraries for 2MB Hugepages used in CSIT.
+#. buffers-per-numa <value> - sets a number of memory buffers allocated
+   to VPP per CPU socket. VPP default is 16384. Needs to be increased for
+   scenarios with large number of interfaces and worker threads. To
+   accommodate for scale tests, CSIT is setting it to the maximum possible
+   value corresponding to the limit of DPDK memory mappings (currently
+   256). For Xeon Skylake platforms configured with 2MB hugepages and VPP
+   data-size and buffer-size defaults (2048B and 2496B respectively), this
+   results in value of 215040 (256 * 840 = 215040, 840 * 2496B buffers fit
+   in 2MB hugepage ). For Xeon Haswell nodes value of 107520 is used.
 
 Per Test Settings
 ~~~~~~~~~~~~~~~~~