PCP: support for 'dynamic columns' added at runtime

Implements support for arbitrary Performance Co-Pilot
metrics with per-process instance domains to form new
htop columns.  The column-to-metric mappings are setup
using configuration files which will be documented via
man pages as part of a follow-up commit.

We provide an initial set of column configurations so
as to provide new capabilities to pcp-htop: including
configs for containers, open fd counts, scheduler run
queue time, tcp/udp bytes/calls sent/recv, delay acct,
virtual machine guests, detailed virtual memory, swap.

Note there is a change to the configuration file path
resolution algorithm introduced for 'dynamic meters'.
First, look in any custom PCP_HTOP_DIR location.  Then
iterate, in priority order, users home directory, then
local sysadmins files in /etc/pcp/htop, then readonly
configuration files below /usr/share/pcp/htop.  This
final location becomes the preferred place for our own
shipped meter and column files.

The Settings file (htoprc) writing code is updated to
not using the numeric identifier for dynamic columns.
The same strategy used for dynamic meters is used here
where we write Dynamic(name) so the name can be setup
once more at start.  Regular (static) columns writing
to htoprc - i.e. numerically indexed - is unchanged.

pcp/columns/container

@@ -0,0 +1,10 @@
+#
+# pcp-htop(1) configuration file - see pcp-htop(5)
+#
+
+[container]
+heading = Container
+caption = CONTAINER
+width = -12
+metric = proc.id.container
+description = Name of processes container via cgroup heuristics

pcp/columns/delayacct

@@ -0,0 +1,10 @@
+#
+# pcp-htop(1) configuration file - see pcp-htop(5)
+#
+
+[blkio]
+heading = BLKIOD
+caption = BLKIO_TIME
+width = 6
+metric = proc.psinfo.delayacct_blkio_time
+description = Aggregated block I/O delays

pcp/columns/fdcount

@@ -0,0 +1,10 @@
+#
+# pcp-htop(1) configuration file - see pcp-htop(5)
+#
+
+[fds]
+heading = FDS
+caption = FDCOUNT
+width = 4
+metric = proc.fd.count
+description = Open file descriptors

pcp/columns/guest

@@ -0,0 +1,17 @@
+#
+# pcp-htop(1) configuration file - see pcp-htop(5)
+#
+
+[guest]
+heading = GUEST
+caption = GUEST_TIME
+width = 6
+metric = proc.psinfo.guest_time
+description = Guest time for the process
+
+[cguest]
+heading = CGUEST
+caption = CGUEST_TIME
+width = 6
+metric = proc.psinfo.guest_time + proc.psinfo.cguest_time
+description = Cumulative guest time for the process and its children

pcp/columns/memory

@@ -0,0 +1,39 @@
+#
+# pcp-htop(1) configuration file - see pcp-htop(5)
+#
+
+[vmdata]
+heading = VDATA
+width = 6
+metric = proc.memory.vmdata
+description = Virtual memory used for data
+
+[vmstack]
+heading = VSTACK
+width = -6
+metric = proc.memory.vmstack
+description = Virtual memory used for stack
+
+[vmexe]
+heading = VEXEC
+width = 6
+metric = proc.memory.vmexe
+description = Virtual memory used for non-library executable code
+
+[vmlib]
+heading = VLIBS
+width = 6
+metric = proc.memory.vmlib
+description = Virtual memory used for libraries
+
+[vmswap]
+heading = VSWAP
+width = 6
+metric = proc.memory.vmswap
+description = Virtual memory size currently swapped out
+
+[vmlock]
+heading = VLOCK
+width = 6
+metric = proc.memory.vmlock
+description = Locked virtual memory

pcp/columns/sched

@@ -0,0 +1,10 @@
+#
+# pcp-htop(1) configuration file - see pcp-htop(5)
+#
+
+[rundelay]
+heading = RUNQ
+caption = RUN_DELAY
+width = 4
+metric = proc.schedstat.run_delay
+description = Run queue time

pcp/columns/swap

@@ -0,0 +1,15 @@
+#
+# pcp-htop(1) configuration file - see pcp-htop(5)
+#
+
+[swap]
+heading = SWAP
+width = 5
+metric = proc.psinfo.nswap
+description = Count of swap operations for the process
+
+[cswap]
+heading = CSWAP
+width = 5
+metric = proc.psinfo.nswap + proc.psinfo.cnswap
+description = Cumulative swap operations for the process and its children

pcp/columns/tcp

@@ -0,0 +1,31 @@
+#
+# pcp-htop(1) configuration file - see pcp-htop(5)
+#
+
+[tcp_send_calls]
+heading = TCPS
+caption = TCP_SEND
+width = 6
+metric = bcc.proc.net.tcp.send.calls
+description = Count of TCP send calls
+
+[tcp_send_bytes]
+heading = TCPSB
+caption = TCP_SEND_BYTES
+width = 6
+metric = bcc.proc.net.tcp.send.bytes
+description = Cumulative bytes sent via TCP
+
+[tcp_recv_calls]
+heading = TCPR
+caption = TCP_RECV
+width = 6
+metric = bcc.proc.net.tcp.recv.calls
+description = Count of TCP recv calls
+
+[tcp_recv_bytes]
+heading = TCPRB
+caption = TCP_RECV_BYTES
+width = 6
+metric = bcc.proc.net.tcp.recv.bytes
+description = Cumulative bytes received via TCP

pcp/columns/udp

@@ -0,0 +1,31 @@
+#
+# pcp-htop(1) configuration file - see pcp-htop(5)
+#
+
+[udp_send_calls]
+heading = UDPS
+caption = UDP_SEND
+width = 6
+metric = bcc.proc.net.udp.send.calls
+description = Count of UDP send calls
+
+[udp_send_bytes]
+heading = UDPSB
+caption = UDP_SEND_BYTES
+width = 6
+metric = bcc.proc.net.udp.send.bytes
+description = Cumulative bytes sent via UDP
+
+[udp_recv_calls]
+heading = UDPR
+caption = UDP_RECV
+width = 6
+metric = bcc.proc.net.udp.recv.calls
+description = Count of UDP recv calls
+
+[udp_recv_bytes]
+heading = UDPRB
+caption = UDP_RECV_BYTES
+width = 6
+metric = bcc.proc.net.udp.recv.bytes
+description = Cumulative bytes received via UDP

pcp/columns/wchan

@@ -0,0 +1,17 @@
+#
+# pcp-htop(1) configuration file - see pcp-htop(5)
+#
+
+[wchan]
+heading = WCHAN
+caption = WCHAN_ADDRESS
+width = 8
+metric = proc.psinfo.wchan
+description = Wait channel, kernel address process is blocked or sleeping on
+
+[wchans]
+heading = WCHANS
+caption = WCHAN_SYMBOL
+width = -12
+metric = proc.psinfo.wchan_s
+description = Wait channel, kernel symbol process is blocked or sleeping on