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.
Adds AGRP (autogroup) and ANI (autogroup nice) columns that
report the information from /proc/PID/autogroup, as well as
handlers for '{' and '}' to change the autogroup nice value.
This is guarded by /proc/sys/kernel/sched_autogroup_enabled
such that sampling and/or changing values wont be attempted
unless the kernel feature is enabled.
Fixes: #720
Remove code now that we have common platform-independent command
line wrangling (thanks BenBE!). Add PCP platform support for a
handful of other recently arriving odds and ends - ELAPSED time,
CWD, and so on.
This introduces an initial platform for extracting metrics
using the PCP performance metrics API - PMAPI(3). It can
be used via the --enable-pcp=yes configure option.
So far I've added support for live localhost metrics only,
and only using pre-defined metrics already found in htop.
If available, all sampling is performed by pmcd(1) - else,
we fallback to htop doing the metric sampling itself (all
below the PMAPI). When pmcd is used, it may be configured
to run children with elevated privileges, so htop does not
need to be setuid (authentication with pmcd is available).
Additionally, the PMAPI allows us to support archives (for
historical analysis and for automated regression tests in
htop). We'll need platform-specific command line argument
additions, which isn't yet feasible in htop (not difficult
to add though).
The goal of this first version is minimal impact in terms
of modifying the htop codebase, to introduce key ideas in
PCP (metric namespace, metadata, APIs and so on) and give
us something to discuss, experiment with and build on.
Sohaib
Nathan Scott