[PATCH 1/2] testparm: Add warning for socket options.

[Andreas Schneider]

Signed-off-by: Andreas Schneider <asn at samba.org>
---
 source3/utils/testparm.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/source3/utils/testparm.c b/source3/utils/testparm.c
index a9793ab..598f589d 100644
--- a/source3/utils/testparm.c
+++ b/source3/utils/testparm.c
@@ -126,6 +126,29 @@ cannot be set in the smb.conf file. nmbd will abort with this setting.\n");
 	}
 
 	/*
+	 * Socket options.
+	 */
+	if (lp_socket_options()) {
+		fprintf(stderr,
+			"WARNING: socket options = %s\n"
+			"Modern server operating systems are tuned for\n"
+			"high network performance in the majority of situations;\n"
+			"when you set 'socket options' you are overriding those\n"
+			"settings.\n"
+			"Linux in particular has an auto-tuning mechanism for\n"
+			"buffer sizes that will be disabled if you specify a\n"
+			"socket buffer size. This can potentially cripple your\n"
+			"TCP/IP stack!!!\n\n"
+			"Getting the 'socket options' correct can make a big\n"
+			"difference to your performance, but getting them wrong\n"
+			"can degrade it by just as much. As with any other low\n"
+			"level setting, if you must make changes to it, make\n "
+			"small changes and test the effect before making any\n"
+			"large changes.\n\n",
+			lp_socket_options());
+	}
+
+	/*
 	 * Password server sanity checks.
 	 */
 
@@ -438,7 +461,9 @@ rameter is ignored when using CUPS libraries.\n",
 
 
 	if (!section_name && !parameter_name) {
-		fprintf(stderr,"Server role: %s\n", server_role_str(lp_server_role()));
+		fprintf(stderr,
+			"Server role: %s\n\n",
+			server_role_str(lp_server_role()));
 	}
 
 	if (!cname) {
-- 
1.8.4