Currently gopsutils fails to indentify the POWER processors family,
returning an almost empty Info() structure.
This patch improves the POWER identification without changing what is
available for x86.
* on virtualized host, this may happen.
* but we may have a value from parsing `/proc/cpuinfo`
* in this case, we do not return the error if we fail to extra
a value from `cpufreq/cpuinfo_max_freq`
* resolve#249
* in `cpu_windows.go`, `Mhz` is the value of `MaxClockSpeed`
* on Linux platform, the `Mhz` value is extracted from `/proc/cpuinfo`
which reflects the current clock speed; treat this as the fallback
value instead
* read from `cpufreq/cpuinfo_max_freq` under sysfs to get the
maximum clock speed for `Mhz`, just like for Windows platform
* also fix the path to `cpu.CoreID` value; the filename is `core_id`
* for Darwin, it is a minor tweak for readability: the value
returned is in Hz, so using a variable named 'hz' makes more
sense than 'mhz'
* for Linux, the unit is in kHz so we need to divide the value
from `cpuinfo_max_freq` by 10^3 to get MHz (see
cpu-freq/user-guide.txt of the kernel documentation)
Package common wasn't used for public functions. Place it in an
internal directory to prevent other packages from using.
Remove the distributed references to "HOST_PROC" and "HOST_SYS"
consts and combine into a common function. This also helps so that
if a env var is defined with a trailing slash all will continue to
work as expected.
Fixes#100
ARM CPUs don't include the same fields as x86 and amd64 CPUs in
the /proc/cpuinfo list. Pull information from the /sys/...
device tree as well as updating when a CPU is done in cpuinfo.
Fixes#88
Added the ability to fetch an alternative location for /proc via an
environment variable. If the env var is not set it will return /proc as
the default value.
