SLAB is a cache mechanism used by the Kernel to avoid fragmentation.
Each internal structure (process, file descriptor, inode...) is stored within a SLAB.
The plugin is disabled by default because it collects and displays a huge amount of metrics.
To enable it set slabinfo = yes in the plugins section of the netdata.conf configuration file.
There is currently no configuration needed for the plugin itself.
As /proc/slabinfo is only readable by root, this plugin is setuid root.
This slabinfo details allows to have clues on actions done on your system.
In the following screenshot, you can clearly see a find done on a ext4 filesystem (the number of ext4_inode_cache & dentry are rising fast), and a few seconds later, an admin issued a echo 3 > /proc/sys/vm/drop_cached as their count dropped.
