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cat /proc/sys/kernel/random/uuid [I ❤️ Linux] (feddit.org)

submitted 3 days ago* (last edited 2 days ago) by [email protected] to c/[email protected]

35 comments fedilink hide all child comments

That's all. I just found this in a random script. Generates a random UUID every time it's called. I didn't know.

Of course I can also use uuidgen or pipe /dev/(u)random into something to get a random alphanumeric string - but this is built right into the kernel!

In /proc/sys/kernel/random/, there's also boot_id which ~~seems to do the same~~ is static, and some tweakable parameters.

❤️🐧

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[–] [email protected] 1 points 3 days ago (3 children)

That reminds me of the CPU stress test I ran many years ago.

dd if=/dev/random of=/dev/null

If you have 8 cores, just open 8 terminals, and run that code in each of them.

[–] [email protected] 4 points 3 days ago

/dev/urandom should stress the CPU more. /dev/random can be entropy limited

[–] [email protected] 2 points 3 days ago (1 children)

Can you guarantee that each process will run on its own core?

[–] [email protected] 2 points 2 days ago

Absolutely not, quite the opposite actually. However, the end result is close to 100% CPU load, which is good enough for some purposes. Let’s say you want to test the performance of your CPU cooler, or overclock stability, this should good enough. There are also dedicated tools for people with more advanced needs.

[–] [email protected] 3 points 3 days ago* (last edited 3 days ago) (1 children)

for i in {1..n}  # where n == number of cores
do
  dd if=/dev/urandom of=/dev/null &
done

# to stop:
jobs -p | xargs kill

[–] [email protected] 1 points 2 days ago (1 children)

Oh yeah. This looks like a much better way to do it. My solution is pretty bare bones by comparison.

[–] [email protected] 1 points 2 days ago

the advantage of yours is that you can actually see the performance number afterwards.