Currently htop does not support offline CPUs and hot-swapping, e.g. via
echo 0 > /sys/devices/system/cpu/cpu2/online
Split the current single cpuCount variable into activeCPUs and
existingCPUs.
Supersedes: #650
Related: #580
This commit is based on exploratory work by Sohaib Mohamed.
The end goal is two-fold - to support addition of Meters we
build via configuration files for both the PCP platform and
for scripts ( https://github.com/htop-dev/htop/issues/526 )
Here, we focus on generic code and the PCP support. A new
class DynamicMeter is introduced - it uses the special case
'param' field handling that previously was used only by the
CPUMeter, such that every runtime-configured Meter is given
a unique identifier. Unlike with the CPUMeter this is used
internally only. When reading/writing to htoprc instead of
CPU(N) - where N is an integer param (CPU number) - we use
the string name for each meter. For example, if we have a
configuration for a DynamicMeter for some Redis metrics, we
might read and write "Dynamic(redis)". This identifier is
subsequently matched (back) up to the configuration file so
we're able to re-create arbitrary user configurations.
The PCP platform configuration file format is fairly simple.
We expand configs from several directories, including the
users homedir alongside htoprc (below htop/meters/) and also
/etc/pcp/htop/meters. The format will be described via a
new pcp-htop(5) man page, but its basically ini-style and
each Meter has one or more metric expressions associated, as
well as specifications for labels, color and so on via a dot
separated notation for individual metrics within the Meter.
A few initial sample configuration files are provided below
./pcp/meters that give the general idea. The PCP "derived"
metric specification - see pmRegisterDerived(3) - is used
as the syntax for specifying metrics in PCP DynamicMeters.
- fill tty name
- fill session id
- show real tgid not adjusted
- drop unimplemented TPGID, MINFLT and MAJFLT
- adjust header width of ZONEID, which get auto-adjusted as a pid-column
The system interfaces kstat_lookup() and kstat_data_lookup() take a
non-constant string parameter, but passing string literals is valid.
Add wrapper functions to ignore all the const-discard warnings.
It is only used on Linux to optimize memory handling in case the command
changes to a smaller-or-equal string.
This "optimization" however causes more code bloat and maintenance cost
on string handling issues than it gains.
By storing the per-process m_resident and m_virt values in the form
htop wants to display them in (KB, not pages), we no longer need to
have definitions of pageSize and pageSizeKB in the common CRT code.
These variables were never really CRT (i.e. display) related in the
first place. It turns out the darwin platform code doesn't need to
use these at all (the process values are extracted from the kernel
in bytes not pages) and the other platforms can each use their own
local pagesize variables, in more appropriate locations.
Some platforms were actually already doing this, so this change is
removing duplication of logic and variables there.
Generic data, as CPU and memory usage, are used by Meters.
In paused mode they would stop receiving updates and especially Graph
Meters would stop showing continuous data.
Improves: #214Closes: #253
man:sysconf(3) states:
The values obtained from these functions are system configuration constants.
They do not change during the lifetime of a process.
Reasoning:
- implementation was unsound -- broke down when I added a fairly
basic macro definition expanding to a struct initializer in a *.c
file.
- made it way too easy (e.g. via otherwise totally innocuous git
commands) to end up with timestamps such that it always ran
MakeHeader.py but never used its output, leading to overbuild noise
when running what should be a null 'make'.
- but mostly: it's just an awkward way of dealing with C code.
