doc: add multiprocess known issue in release notes

Also, reference Bugzilla entry for keeping most current information in
one place.

Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: John McNamara <john.mcnamara@intel.com>

diff --git a/doc/guides/rel_notes/release_18_05.rst b/doc/guides/rel_notes/release_18_05.rst
index c777291..ffab503 100644 (file)
--- a/doc/guides/rel_notes/release_18_05.rst
+++ b/doc/guides/rel_notes/release_18_05.rst
@@ -588,6 +588,19 @@ Known Issues
    Also, make sure to start the actual text at the margin.
    =========================================================
 
+* **Secondary process launch is not reliable.**
+
+  Recent memory hotplug patches have made multiprocess startup less reliable
+  than it was in the past. A number of workarounds are known to work depending
+  on the circumstances. As such it isn't recommended to use the secondary
+  process mechanism for critical systems. The underlying issues will be
+  addressed in upcoming releases.
+
+  The issue is explained in more detail, including potential workarounds,
+  in the Bugzilla entry referenced below.
+
+  Bugzilla entry: https://dpdk.org/tracker/show_bug.cgi?id=50
+
 * **pdump is not compatible with old applications.**
 
   As we changed to use generic multi-process communication for pdump negotiation