Create separate sub-window listing each MDT

Create a separate sub-window which lists each MDT, as already existed
for OSTs.  Like the existing OST sub-window, the MDT sub-window supports
sorting, collapsing MDTs to MDSs, and scrolling when there are more rows
to display than rows available on the terminal.

For scrolling and selecting the sort column, the user switches between
the MDT and OST sub-windows via 'z' or 'Z'.  This, and the new keys
introduced for selecting an MDT sort column, are listed in the help
display.

If room is available in the terminal window, the summary as well as rows
for each MDT and OST are displayed.

Otherwise, the MDT sub-window and OST sub-window sizes are adjusted to
fit in the available space.  The MDT and OST sections each occupy a
number of rows, respectively, proportional to the MDT and OST counts.

Updated manpage to reflect new sub-window and keys.

utils/ltop.1.in

@@ -24,6 +24,38 @@ Log raw data from the session to FILE, so it can be played back with \fI\-p\fR.
 .I "-p,--play FILE"
 Play back raw data from FILE recorded with \fI\-r\fR or with the
 interactive \fIR\fR command.
+.SH "MDT FIELD DESCRIPTIONS"
+.TP
+\fIMDT\fR
+The mdt index, in hex.  In the compressed view (c below), the number of MDT's
+on the MDS is displayed in parenthesis.
+.TP
+\fIMDS\fR
+The MDS hostname.
+.TP
+\fIOpen\fR
+The number of file opens per second.
+.TP
+\fIClose\fR
+The number of file closes per second.
+.TP
+\fIGetattr\fR
+The number of file or directory getattrs per second.
+.TP
+\fISetattr\fR
+The number of file or directory setattrs per second.
+.TP
+\fIUnlink\fR
+The number of file unlinks per second.
+.TP
+\fIMkdir\fR
+The number of mkdirs per second.
+.TP
+\fIRmdir\fR
+The number of rmdirs per second.
+.TP
+\fIRename\fR
+The number of files or directories renamed per second.
 .SH "OST FIELD DESCRIPTIONS"
 .TP
 \fIOST\fR
@@ -66,14 +98,15 @@ The lock grant rate.
 \fILCR\fR
 The lock cancellation rate.
 .TP
+\fI%spc
+The percentage of OST storage space in use.
+.SH "COMMON FIELD DESCRIPTIONS"
+.TP
 \fI%cpu
-The percentage of cpu in use on the OSS.
+The percentage of cpu in use on the server.
 .TP
 \fI%mem
-The percentage of memory in use on the OSS.
-.TP
-\fI%spc
-The percentage of OST storage space in use.
+The percentage of memory in use on the server.
 .SH "INTERACTIVE COMMANDS"
 .B ltop
 responds to the following single character commands interactively:
@@ -84,61 +117,89 @@ Terminate the
 program.
 .TP
 \fIPageDown\fR
-Page down through OST information if it won't fit on screen.
+Page down through target information if it won't fit on screen.
 .TP
 \fIPageUp\fR
-Page up through OST information if it won't fit on screen.
+Page up through target information if it won't fit on screen.
 .TP
 \fIc\fR
-Toggle compressed OST view.  The default mode is to display one line per OST.
-In compressed mode, one line per OSS is displayed.  Numerical data is summed
-in the OSS view except for the export count where the minimum export count
-of any OST is displayed.  Also if any of the OST's is in recovery, recovery
-information for that OST will be shown in the OSS view.
+Toggle compressed target view.  The default mode is to display one line per
+target.  In compressed mode, one line per server is displayed.  Numerical data
+is summed in the server view except for the export count where the minimum
+export count of any target is displayed.  Also if any of the target's is in
+recovery, recovery information for that target will be shown in the server
+view.
 .TP
 \fI>\fR
-Sort OST/OSS view by the next field to the right, wrapping around at the end.
-Initially, entries are sorted by the leftmost field, OST index.
+Sort MDT/OST window by the next field to the right, wrapping around at the end.
+Initially, entries are sorted by the leftmost field, OST/MDT index.
 .TP
 \fI<\fR
-Sort OST/OSS view by the next field to the left, wrapping around at the end.
-Initially, entries are sorted by the leftmost field, OST index.
+Sort MDT/OST window by the next field to the left, wrapping around at the end.
+Initially, entries are sorted by the leftmost field, OST/MDT index.
+.TP
+\fIt\fR
+Sort by target index, ascending order.
 .TP
 \fIs\fR
-Sort by OSS name, ascending order.
+Sort by server name, ascending order.
 .TP
 \fIx\fR
 Sort by export count, ascending order.
 .TP
 \fIC\fR
-Sort by (re-)connect rate, descending order.
+Sort by (re-)connect rate, descending order (OST).
 .TP
 \fIr\fR
-Sort by read bandwidth, descending order.
+Sort by read bandwidth, descending order (OST).
 .TP
 \fIw\fR
-Sort by write bandwidth, descending order.
+Sort by write bandwidth, descending order (OST).
 .TP
 \fIi\fR
-Sort by IOPS, descending order.
+Sort by IOPS, descending order (OST).
 .TP
 \fIl\fR
-Sort by lock count, descending order.
+Sort by lock count, descending order (OST).
 .TP
 \fIg\fR
-Sort by lock grant rate, descending order.
+Sort by lock grant rate, descending order (OST).
 .TP
 \fIL\fR
-Sort by lock cancellation rate, descending order.
+Sort by lock cancellation rate, descending order (OST).
+.TP
+\fIo\fR
+Sort by file open rate, descending order (MDT).
+.TP
+\fIC\fR
+Sort by file close rate, descending order (MDT).
+.TP
+\fIg\fR
+Sort by getattr rate, descending order (MDT).
+.TP
+\fIS\fR
+Sort by setattr rate, descending order (MDT).
+.TP
+\fIU\fR
+Sort by file unlink rate, descending order (MDT).
+.TP
+\fIM\fR
+Sort by mkdir rate, descending order (MDT).
+.TP
+\fIr\fR
+Sort by rmdir rate, descending order (MDT).
+.TP
+\fIR\fR
+Sort by rename rate, descending order (MDT).
 .TP
 \fIu\fR
 Sort by percent cpu utilization, descending order.
 .TP
 \fIm\fR
-Sort by percent memory utilization , descending order.
+Sort by percent memory utilization, descending order.
 .TP
 \fIS\fR
-Sort by percent disk space utilization , descending order.
+Sort by percent disk space utilization, descending order (OST).
 .TP
 \fIDOWN\fR
 Move cursor down.