Check manual page of mem.vmalloc
Usage of Vmalloc address space
The linux kernel keeps a part of the available address
space free for usage by device drivers, e.g. for address
mappings of IO devices into the physical address space.
An example is the graphics driver used by the X server,
which needs address mappings for communicating with
the hardware. In /proc/meminfo that area is called
VmallocTotal. On 32 bit architectures this area has
a very limited size and is subject to fragmentation or
consumption by buggy graphics drivers.
This check monitors the current usage of the the vmalloc
address space and also the size of the largest available
chunk (indicating the degree of fragmentation).
A check is created if VmallocTotal is available in
/proc/meminfo and only if the total size of the vmalloc
area is less then 4 GB. This is generally only possible
for 32 bit architectures.
Please add mem.vmalloc to ignored_checktypes
if you do not need this check.