Merge branch '1879-fix-documentation-on-named--U' into 'main'

Properly document that named -U <n> is no-op now

Closes #1879

See merge request isc-projects/bind9!8976

CHANGES

@@ -1,3 +1,8 @@
+6378.	[func]		The option to specify the number of UDP dispatches was
+			previously removed. An attempt to use the option now prints
+			a warning.
+			[GL #1879]
+
 6377.	[func]		Introduce 'dnssec-ksr', a DNSSEC tool to create
 			Key Signing Requests (KSRs) and Signed Key Responses
 			(SKRs). [GL #1128]

bin/named/main.c

@@ -949,6 +949,7 @@ parse_command_line(int argc, char *argv[]) {
 			break;
 		case 'U':
 			/* Obsolete.  No longer in use.  Ignore. */
+			named_main_earlywarning("option '-U' has been removed");
 			break;
 		case 'u':
 			named_g_username = isc_commandline_argument;

bin/named/named.rst

@@ -21,7 +21,7 @@ named - Internet domain name server
 Synopsis
 ~~~~~~~~
 
-:program:`named` [ [**-4**] | [**-6**] ] [**-c** config-file] [**-C**] [**-d** debug-level] [**-D** string] [**-E** engine-name] [**-f**] [**-g**] [**-L** logfile] [**-M** option] [**-m** flag] [**-n** #cpus] [**-p** port] [**-s**] [**-t** directory] [**-U** #listeners] [**-u** user] [**-v**] [**-V**] ]
+:program:`named` [ [**-4**] | [**-6**] ] [**-c** config-file] [**-C**] [**-d** debug-level] [**-D** string] [**-E** engine-name] [**-f**] [**-g**] [**-L** logfile] [**-M** option] [**-m** flag] [**-n** #cpus] [**-p** port] [**-s**] [**-t** directory] [**-u** user] [**-v**] [**-V**] ]
 
 Description
 ~~~~~~~~~~~
@@ -163,14 +163,7 @@ Options
 
 .. option:: -U #listeners
 
-   This option tells :program:`named` the number of ``#listeners`` worker threads to listen on, for incoming UDP packets on
-   each address. If not specified, :program:`named` calculates a default
-   value based on the number of detected CPUs: 1 for 1 CPU, and the
-   number of detected CPUs minus one for machines with more than 1 CPU.
-   This cannot be increased to a value higher than the number of CPUs.
-   If :option:`-n` has been set to a higher value than the number of detected
-   CPUs, then :option:`-U` may be increased as high as that value, but no
-   higher.
+   This option has been removed. Attempts to use it now result in a warning.
 
 .. option:: -u user
 

doc/notes/notes-current.rst

@@ -29,7 +29,8 @@ New Features
 Removed Features
 ~~~~~~~~~~~~~~~~
 
-- None.
+- The ``named`` command line option ``-U <n>``, which specified the number of UDP dispatches,
+  has been removed. Using it now prints a warning.  :gl:`#1879`
 
 Feature Changes
 ~~~~~~~~~~~~~~~