[SOLVED] Slow ZFS encryption: will we get a fix for AVX/AVX2 not being selected?

meyergru

New Member
Jan 28, 2023
29
2
3
There is an ongoing discussion about slow encrypted ZFS performance, e.g. here: https://github.com/openzfs/zfs/issues/15245 and here: https://github.com/openzfs/zfs/issues/15276

Obviously this is due to a regression introduced in kernel 5.15.0-82 and discussed here: https://lore.kernel.org/lkml/87r0nsddb5.ffs@tglx/T/#m3407d88a81289c7f94cc1e09bf27c3b1229ce87e

It leads to AVX and AVX2 instruction sets not being used for OpenZFS encryption and slowing things down for modern CPUs. You can check if "cat /sys/module/icp/parameters/icp_gcm_impl" includes AVX if your CPU has it (i.e. "cat /proc/cpuinfo" contains AVX.

An upstream patch has been included in kernel 6.1.50 (look for "x86/fpu: Set X86_FEATURE_OSXSAVE feature after enabling OSXSAVE in CR4" in https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.1.50), but not for any upstream 6.2 kernel. The upstream commit is 2c66ca3949dc701da7f4c9407f2140ae425683a5.

Alas, since PVE 8 kernels are based on 6.2.16, this has not yet landed here. Can we expect this to be included in the near future pve-kernel-6.2?

P.S.: 6.2.16-10 and 6.2.16-12 are affected, whereas 6.2.16-6 (which really is 6.2.16-5) is not.
 
Last edited:
You probably already saw that - but for the people only reading here and not on github/openzfs

the next version of Proxmox kernels (6.2.16-14) will contain the cherry-picked fix (already confirmed to fix the regression, but currently still in internal testing)

https://github.com/openzfs/zfs/issues/15223
 
  • Like
Reactions: meyergru

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get yours easily in our online shop.

Buy now!