Suggested by Hugh Dickins. Thanks.
Signed-off-by: Karel Zak <kzak@redhat.com>
It is formatted as a comma separated list of options. It contains at least
the type of mount plus any additional options appropriate to the filesystem
-type. For documentation on the available options, see
+type. For documentation on the available mount options, see
.BR mount (8).
+For documentation on the available swap options, see
+.BR swapon (8).
+
Basic file system independent options are:
.TP
.B defaults
Devices that are already being used as swap are silently skipped.
.TP
.B "\-d, \-\-discard"
-Swapping will discard clusters of swap pages in between freeing them
-and re-writing to them, if the swap device supports that.
+Discard freed swap pages before they are reused, if the swap
+device supports the discard or trim operation. This may improve
+performance on some Solid State Devices, but often it does not.
The
.I /etc/fstab
mount option
.BI discard
may be also used to enable discard flag.
-
.TP
.B "\-e, \-\-ifexists"
Silently skip devices that do not exist.