Improve Memory Detection

[wdelgenio]

Instead of guessing how much memory a system has from /proc/meminfo, it's possible to get an exact value using sysfs.

For example, the lshw util queries the /sys/devices/system/memory dir for available memory blocks and uses /sys/devices/system/memory/block_size_bytes as the block size. Check that each memory block is online by checking the value of /sys/devices/system/memory/memory*/online

Here's the documentation on the sysfs memory blocks https://www.ibm.com/support/knowledgecenter/en/linuxonibm/com.ibm.linux.z.lgdd/lgdd_c_mem_know_sysfs.html

Here's a one-liner:
printf '%c' /sys/devices/system/memory/memory*/online | wc -c | dc -e '?16i' -f /sys/devices/system/memory/block_size_bytes -e '*p' | numfmt --to=iec-i --suffix B