On Wed, Sep 2, 2020, 12:16 PM Adam Williamson <adamwill@fedoraproject.org> wrote:
On Sat, 2020-08-29 at 21:27 -0600, Chris Murphy wrote:
> Hi,
> These are based on Fedora-Workstation-Live-x86_64-33-20200828.n.0.iso
> in a VM. The numbers are different on bare metal but correlate.
> The only standout is rngd.service. That's a pretty big single hit,
> percentage wise. And I don't know if we even need it anymore. Among
> the rest, perhaps atd.service and crond.service could be disabled by
> default on new installations, in favor of systemd timers.

Well, what rngd does is highly system dependent, and in a VM it's gonna
depend to a degree on exactly how the VM is configured (whether you
attach some kind of virtual hwrng to the VM and if so how it's set up
exactly). You'd want some data from real systems and probably different
VM configs before deciding rngd is a big problem.

rngd has come up before for removal


I have a laptop that was once negatively affected by rngd's removal, but it hasn't been that way in any of my f33 testing with it removed - I assume due to the somewhat recent kernel changes to making sufficient entropy available in early boot.

I've tested default virt-manager and GNOME Boxes environments; two different makes of laptop; and a different make of desktop. All are delayed by 2-4 seconds when enabled. And none are improved.

But it's valid to understand if this high cost has some sort of on-going value.

And I also haven't tested at all on other archs.

Anyway, Workstation WG has a proposal to remove it.

Chris Murphy