add linux kernel version note

diff --git a/README b/README
index 409bcb7bd1c6c21dab11e8a62419ac41b427b884..9e29324d95cfa60a79d3af506222d6bef503fc5c 100644 (file)
--- a/README
+++ b/README
@@ -174,7 +174,8 @@ Building
 
            CFLAGS
                C compiler flags.  Defaults to include -g and/or -O2
-               as supported by the compiler.  
+               as supported by the compiler.  Please include '-g'
+               if you need to set CFLAGS.
 
            STD_CINCLUDES
                System header file directories.  Can be used to specify
@@ -291,6 +292,10 @@ Building
        libraries.  sh-utils-1.16 provides a "printf" which compiles
        on SunOS 4.
 
+Known limitations
+
+       Linux requires kernel build 2.6.39 or later to get the
+       performance benefits from using multiple sockets.
 
 Documentation