SteamOS 3.6..0 Preview uses zram, breaks CryoUtilities swap management

[omor1]

SteamOS 3.6.0 uses zram; since this has higher priority than the swap file, this breaks getSwapFileLocation.

It's a bit unclear to me if zram is being used instead of, or in addition to the swap file.
This might also impact recommended swappiness: since swap is in compressed memory, it's much cheaper to write to/read from and it might mean it's better to proactively push less frequently used memory to zram.

[CryoByte33]

Good catch, I haven't had the time to try 3.6 preview, but it was working on main just a month or 2 ago, so Valve must have made another change. I have an update nearly ready for CU so I'll try to batch this in.

As for swappiness, it shouldn't make that much of a difference since raw RAM and ZRAM will both operate at similar speeds, but ZRAM will benefit from additional compression. As long as the swap devices have the correct precedence, you should see similar performance, but as always I will have to test to make sure.

[CryoByte33]

As an aside, I recently got a new job and have been very busy, sorry for what seems like no work on this project, I've just been doing a lot on a private testing repo since I made a lot of breaking changes :)

[krozgrov]

Does that mean to uninstall if upgrading to 3.6.0? Or can we keep cryo installed just knowing that zram is being used?

[CryoByte33]

Does that mean to uninstall if upgrading to 3.6.0? Or can we keep cryo installed just knowing that zram is being used?

CU should still be safe on 3.6, just avoid the swap resize function until a permanent fix is out. Aside from that you should be set, to the best of my knowledge.