memtester (memory test utility)

memtester is a userspace utility for testing the memory subsystem
for faults. Unlike memtest86, it runs as a process on a running Linux
system, meaning it can't test all of memory the way memtest86 is able
to... but you don't have to reboot to use it.

Note that, by definition, memtester counts as a denial-of-service
(resource exhaustion) attack against the local machine. Be cautious
about using it, and definitely *read its man page* before use.

memtester has traditionally been run as root, so that it can lock the
memory it's testing to prevent swapping and remapping. However, it's
possible to use capabilities to allow it to run correctly as a normal
user. Use something like:

# chown root:console /usr/bin/memtester
# chmod 0750 /usr/bin/memtester
# setcap cap_ipc_lock=ep /usr/bin/memtester

This allows anyone in the "console" group to run memtester. You could
also create a memtester group and use it in the chown command above,
if you'd rather have more fine-grained control.