| 20 Dec 2024 |
 matthewcroughan @fosdem | Gets very far, and then fails on the CPU at conv2d(), works fine on the host outside of a VM in the same seutp | 11:23:26 |
| matthewcroughan @fosdem | looks like it might be avx stuff | 13:00:48 |
| matthewcroughan @fosdem | ah no, I gave it avx and it still complains like this | 13:08:35 |
| matthewcroughan @fosdem | how odd | 13:08:36 |
| matthewcroughan @fosdem | Do we have any existing VM Tests that test torch? | 13:09:05 |
| matthewcroughan @fosdem | looks like we don't actually | 13:10:16 |
| matthewcroughan @fosdem | https://github.com/pytorch/pytorch/blob/main/torch/nn/modules/conv.py | 13:15:03 |
| matthewcroughan @fosdem | ultimately it complains about this | 13:15:07 |
 SomeoneSerge (back on matrix) | No VM tests, no | 13:19:16 |
| matthewcroughan @fosdem | This is the first one I'm trying to execute entirely on the CPU | 13:20:32 |
| matthewcroughan @fosdem | for comfyui in particular | 13:20:39 |
| matthewcroughan @fosdem | 
Download image.png | 13:21:14 |
| matthewcroughan @fosdem | I have this cat that I can reproduce on the host cpu in 13 seconds only | 13:21:17 |
| matthewcroughan @fosdem | comfyui is launched with --cpu but maybe that is incomplete | 13:21:31 |
| matthewcroughan @fosdem | Maybe it secretly still accesses the GPU and this vm test proves it | 13:21:41 |
| SomeoneSerge (back on matrix) | Plausible, I suppose pytorch could ignore our flags and build something with vector extensions on (unless cc-wrapper filters those, I'm not sure), but what part of the logs suggested this conclusion?
Searching for "qemu avx" I see https://superuser.com/a/454814 suggesting -cpu sandyBridge,+avx,enforce
| 13:23:54 |
| SomeoneSerge (back on matrix) | oh i'm acting like an llm | 13:24:16 |
| matthewcroughan @fosdem | Yeah I've done all of that, and lspcu inside the vm shows
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Address sizes: 48 bits physical, 48 bits virtual
Byte Order: Little Endian
CPU(s): 8
On-line CPU(s) list: 0-7
Vendor ID: AuthenticAMD
BIOS Vendor ID: QEMU
Model name: AMD Ryzen 9 3900X 12-Core Processor
BIOS Model name: pc-i440fx-9.1 CPU @ 2.0GHz
BIOS CPU family: 1
CPU family: 23
Model: 113
Thread(s) per core: 1
Core(s) per socket: 8
Socket(s): 1
Stepping: 0
BogoMIPS: 7599.99
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge m
ca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall
nx mmxext fxsr_opt pdpe1gb rdtscp lm rep_good nopl cp
uid extd_apicid tsc_known_freq pni pclmulqdq ssse3 fma
cx16 sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_t
imer aes xsave avx f16c rdrand hypervisor lahf_lm cmp_
legacy svm cr8_legacy abm sse4a misalignsse 3dnowprefe
tch osvw perfctr_core ssbd ibpb stibp vmmcall fsgsbase
tsc_adjust bmi1 avx2 smep bmi2 rdseed adx smap clflus
hopt clwb sha_ni xsaveopt xsavec xgetbv1 clzero xsavee
rptr wbnoinvd arat npt lbrv nrip_save tsc_scale vmcb_c
lean flushbyasid pausefilter pfthreshold v_vmsave_vmlo
ad vgif umip rdpid overflow_recov succor arch_capabili
ties
Virtualization features:
| 13:24:36 |
| matthewcroughan @fosdem | so I supposedly have it | 13:24:44 |
| matthewcroughan @fosdem | I've tried a lot of -cpu options too | 13:26:40 |
| matthewcroughan @fosdem | maybe there's a PYTORCH_VAR I can set? | 13:26:59 |
| SomeoneSerge (back on matrix) |
avx ... but what part of the logs suggested this conclusion?
| 13:38:07 |
| matthewcroughan @fosdem | Nothing, just other people's reports online | 13:38:17 |
| matthewcroughan @fosdem | That are now lost to my browser history | 13:40:38 |
