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.
Refactor the sample time code to make one call to gettimeofday
(aka the realtime clock in clock_gettime, when available) and
one to the monotonic clock. Stores each in more appropriately
named ProcessList fields for ready access when needed. Every
platform gets the opportunity to provide their own clock code,
and the existing Mac OS X specific code is moved below darwin
instead of in Compat.
A couple of leftover time(2) calls are converted to use these
ProcessList fields as well, instead of yet again sampling the
system clock.
Related to https://github.com/htop-dev/htop/pull/574
Currently the tree-view is empty on OpenBSD when kernel threads are
hidden, cause the kernel thread 'swapper' has pid 0 and gets treated as
root of the tree and parent of 'init'.
Do not build any tree with a pid 0 root node.
The local stack buffer does not need to be cleaned to zeros when
- just initialized, cause the length is set to 0 and the first
character is set to '\0', so all printing functions will safely stop
- no further used, i.e. the variable goes out of scope
- stay in follow mode on sort inversion (I)
- stay in follow mode after viewing help screen (h)
- select parent process (where available) when having followed a thread
and hiding these (H)
Closes: #560
If the last process entry is selected and the process dies, stay at the
end of the list and do not jump to the start.
Also if the last entry is selected keep, after rebuilding the process
list due to a new scan, the last entry selected.
Implements the suggestion from https://github.com/htop-dev/htop/issues/399#issuecomment-747861013
Thanks to the refactors from 0bd5c8fb5da and 6393baa74e5, this was really easy
and clean to do.
It maintains the "Tree view always by PID" option in the Settings, which
results in some specific behaviors such as "clicking on the column header to
exit tree view" and "picking a new sort order to exit tree view", for the sake
of the muscle memory of long time htop users. :)
RichString_writeFrom takes a top spot during performance analysis due to the
calls to mbstowcs() and iswprint().
Most of the time we know in advance that we are only going to print regular
ASCII characters.
Christian Göttsche