Re: [PATCH v2] x86/amd: Disable RDSEED on AMD Zen5 because of an error.

[Jason A. Donenfeld]

Hi Thiago,

On Fri, Nov 07, 2025 at 11:55:35AM -0800, Thiago Macieira wrote:
> I'm not asking about the performance of generating new random numbers in this 
> process.
> 
> I am asking about the system-wide impact that draining the entropy source 
> would have. Is that a bad thing?
> 
> I suspect the answer is "no" because it's the same as /dev/urandom anyway.

Oh. "Entropy source draining" is not a real thing. There used to be
bizarre behavior related to /dev/random (not urandom), but this has been
gone for ages. And even the non-getrandom Linux fallback code uses
/dev/urandom before /dev/random. So not even on old kernels is this an
issue. You can keep generating random numbers forever without worrying
about running out of juice or irritating other processes.

Jason