| 3 Jan 2024 |
 K900 | Just so you always have resources left for the host system | 10:57:13 |
| K900 | In case the guest decides to use up all of them | 10:57:22 |
 crushing-smite | yeah, that one I know | 10:58:44 |
| crushing-smite | Like, there is absolutely nothing left of some know-how? | 10:59:14 |
| crushing-smite | which involves tinkering with XML configs | 10:59:26 |
| crushing-smite | (guess those are already wrapped by nix options) | 10:59:36 |
| K900 | I'm sure you can find like | 10:59:46 |
 @atemu12:matrix.org | In reply to @k900:0upti.me
There isn't really much to tweak Hahaha no | 10:59:58 |
| K900 | Reddit threads telling you about the one magic knob that makes everything 0.075% faster trust me bro my uncle works at qemu | 11:00:02 |
| @atemu12:matrix.org | There's lots to tweak if you want decent CPU performance | 11:00:11 |
| @atemu12:matrix.org | Or a stutter-free experience | 11:00:22 |
| @atemu12:matrix.org | You need to pin virtual cores to real cores and set up hugepages as a bare minimum | 11:00:52 |
| @atemu12:matrix.org | I'm sure there's more, I have stopped bothering with it at some point because my games all work on Linux these days | 11:01:26 |
| crushing-smite | In reply to @atemu12:matrix.org
There's lots to tweak if you want decent CPU performance I do | 11:01:30 |
| crushing-smite | In reply to @atemu12:matrix.org
Or a stutter-free experience I do | 11:01:35 |
| crushing-smite | In reply to @atemu12:matrix.org
I'm sure there's more, I have stopped bothering with it at some point because my games all work on Linux these days Please tell :( | 11:01:44 |
| @atemu12:matrix.org | Again, there's thousands of guides on that | 11:01:57 |
| crushing-smite | so google "site:reddit.com kvm windows gaming"? | 11:02:20 |
| @atemu12:matrix.org | /r/VFIO | 11:02:37 |
| @atemu12:matrix.org | And the Arch Wiki | 11:02:41 |
| K900 | I feel like most of that info is very outdated by now, because QEMU definitely uses THP by default now | 11:02:44 |
| @atemu12:matrix.org | You need to set that up on the host side however | 11:03:05 |
| crushing-smite | what's THP, and what was before it? | 11:03:07 |
| K900 | I'm not sure how much impact CPU pinning will have, probably some, but also probably not a lot unless there's contention | 11:03:10 |
| K900 | In reply to@atemu12:matrix.org
You need to set that up on the host side however NixOS defaults to madvise | 11:03:45 |
| K900 | Which QEMU can use | 11:03:48 |
| @atemu12:matrix.org | And you need to set up HP manually because QEMU's THP might not actually use HP if memory is too fragmented and defrag can't be done with PCIe passthru | 11:03:58 |
| K900 | In reply to@crushing-smite:matrix.org
what's THP, and what was before it? THP is "transparent huge pages", which basically means the kernel manages memory in bigger chunks | 11:04:04 |
| @atemu12:matrix.org | In reply to @atemu12:matrix.org
And you need to set up HP manually because QEMU's THP might not actually use HP if memory is too fragmented and defrag can't be done with PCIe passthru Defrag at a later time that is | 11:04:50 |
| K900 | https://developers.redhat.com/blog/2021/04/27/benchmarking-transparent-versus-1gib-static-huge-page-performance-in-linux-virtual-machines#benchmarks | 11:04:58 |
