Adapted version of

commit 65801d02a482befd2745c792d6596ec75d434934
Author: Dan Williams <dcbw@redhat.com>
Date:   Mon Apr 10 12:35:18 2017 -0500

    iptables-restore.8: document -w/-W options
    
    Fixes: 999eaa241212 ("iptables-restore: support acquiring the lock.")
    Signed-off-by: Dan Williams <dcbw@redhat.com>
    Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff -up iptables-1.4.21/iptables/iptables-restore.8.in.restore_wait_man iptables-1.4.21/iptables/iptables-restore.8.in
--- iptables-1.4.21/iptables/iptables-restore.8.in.restore_wait_man	2017-04-20 17:33:23.386401192 +0200
+++ iptables-1.4.21/iptables/iptables-restore.8.in	2017-04-20 17:35:13.562713997 +0200
@@ -23,9 +23,11 @@ iptables-restore \(em Restore IP Tables
 .P
 ip6tables-restore \(em Restore IPv6 Tables
 .SH SYNOPSIS
-\fBiptables\-restore\fP [\fB\-chntvV\fP] [\fB\-M\fP \fImodprobe\fP]
+\fBiptables\-restore\fP [\fB\-chntvV\fP] [\fB\-w\fP \fIsecs\fP]
++[\fB\-W\fP \fIusecs\fP] [\fB\-M\fP \fImodprobe\fP]
 .P
-\fBip6tables\-restore\fP [\fB\-chntvV\fP] [\fB\-M\fP \fImodprobe\fP]
+\fBip6tables\-restore\fP [\fB\-chntvV\fP] [\fB\-w\fP \fIsecs\fP]
++[\fB\-W\fP \fIusecs\fP] [\fB\-M\fP \fImodprobe\fP]
 [\fB\-T\fP \fIname\fP]
 .SH DESCRIPTION
 .PP
@@ -54,6 +56,21 @@ Print additional debug info during rules
 \fB\-V\fP, \fB\-\-version\fP
 Print the program version number.
 .TP
+\fB\-w\fP, \fB\-\-wait\fP [\fIseconds\fP]
+Wait for the xtables lock.
+To prevent multiple instances of the program from running concurrently,
+an attempt will be made to obtain an exclusive lock at launch.  By default,
+the program will exit if the lock cannot be obtained.  This option will
+make the program wait (indefinitely or for optional \fIseconds\fP) until
+the exclusive lock can be obtained.
+.TP
+\fB\-W\fP, \fB\-\-wait-interval\fP \fImicroseconds\fP
+Interval to wait per each iteration.
+When running latency sensitive applications, waiting for the xtables lock
+for extended durations may not be acceptable. This option will make each
+iteration take the amount of time specified. The default interval is
+1 second. This option only works with \fB\-w\fP.
+.TP
 \fB\-M\fP, \fB\-\-modprobe\fP \fImodprobe_program\fP
 Specify the path to the modprobe program. By default, iptables-restore will
 inspect /proc/sys/kernel/modprobe to determine the executable's path.