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mokkurkalve

Member

From: Bergen, Norway

Registered: 2009-08-29

Posts: 60

linux-zen 5.18 entropy_avail

I installed linux-zen 5.18.zen1-1. I also have rngd.service running. I now consistently see these values:

cat /proc/sys/kernel/random/entropy_avail 
256
cat /proc/sys/kernel/random/poolsize 
256
cat /proc/sys/kernel/random/write_wakeup_threshold 
256

Testing /dev/random things seem to work normally. Entropy are produced and looks good with quick test. The display of this value surely must be something wrong with proc after the redesign of the random subsystem? (Before these values would have been something like 3368 4096 2048 with rngd running.)
Does anybody have a clue what  all this is about?

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"ONLY THOSE WHO ATTEMPT THE IMPOSSIBLE WILL ACHIEVE THE ABSURD"
- Oceania Association of Autonomous Astronauts

loqs

Member

Registered: 2014-03-06

Posts: 17,327

Re: linux-zen 5.18 entropy_avail

See https://kernelnewbies.org/Linux_5.18#Security and https://git.kernel.org/pub/scm/linux/ke … 624d73fac6 and https://git.kernel.org/pub/scm/linux/ke … 2cb1893e3f

Last edited by loqs (2022-05-28 12:10:09)

mokkurkalve

Member

From: Bergen, Norway

Registered: 2009-08-29

Posts: 60

Re: linux-zen 5.18 entropy_avail

Mm. So polling these values simply has no meaning in the new world? Does running rngd have any value anymore in this world?

---

"ONLY THOSE WHO ATTEMPT THE IMPOSSIBLE WILL ACHIEVE THE ABSURD"
- Oceania Association of Autonomous Astronauts

loqs

Member

Registered: 2014-03-06

Posts: 17,327

Re: linux-zen 5.18 entropy_avail

Mm. So polling these values simply has no meaning in the new world? Does running rngd have any value anymore in this world?

Does disabling rngd make any difference to the polled values?  I suspect if it still makes a difference now it will stop making one with 5.19 due to https://github.com/torvalds/linux/commi … 76d6aa1c6b

Last edited by loqs (2022-05-28 22:54:30)

mokkurkalve

Member

From: Bergen, Norway

Registered: 2009-08-29

Posts: 60

Re: linux-zen 5.18 entropy_avail

Does disabling rngd make any difference to the polled values?  I suspect if it still makes a difference now it will stop making one with 5.19 due to https://github.com/torvalds/linux/commi … 76d6aa1c6b

Seems this goes into 5.18.1 already, together with a bunch of other random-related stuff:
https://cdn.kernel.org/pub/linux/kernel … Log-5.18.1

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"ONLY THOSE WHO ATTEMPT THE IMPOSSIBLE WILL ACHIEVE THE ABSURD"
- Oceania Association of Autonomous Astronauts

loqs

Member

Registered: 2014-03-06

Posts: 17,327

Re: linux-zen 5.18 entropy_avail

I would suggest discussing the issue with the rng-tools authors at https://github.com/nhorman/rng-tools