/proc/[diskstats|meminfo|stat] get sampled and written to the same
proc_<filename>.log files as during normal bootchat logging. This will
allow rendering the CPU, disk and memory usage charts.
Right now sampling happens once a second, triggered by the heartbeat
event.That produces quite a bit of data for long builds, which will be
addressed in a separate commit by storing the data in a more compact
form.
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
