Wishlist: Display CPU/RAM<->VRAM throughput?

[T-X]

I have an eGPU here. Which usually works great, seemingly until a game overallocates VRAM. Sometimes the amdgpu+Mesa seem to do a good job to swap from VRAM to RAM, sometimes not.

It would be great to have a way to check how much the Thunderbolt 3 port is saturated, maybe in radeontop? So that I would know if this is the bottleneck in a specific situation. Right now I see no way to check this on Linux (usbmon does not work for my USB4 USB-C port).

[clbr]

I'm not sure where this info would be available, but certainly it's not in the GPU registers we use to display the info. As such it would be out of scope for radeontop. You should probably look at your thunderbolt controller. It may expose something in /sys, or if it has datasheets available.

[Umio-Yasuno]

We can check the evicted VRAM size per process from fdinfo.

https://github.com/torvalds/linux/blob/master/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c

0000:08:00.0 (AMD Radeon Graphics), VRAM    28/  512 MiB, GTT  5048/ 7680 MiB
    memtest_vulkan  (   5195), VRAM     0 MiB (  0%), GTT  5034 MiB ( 65%)
                    Requested: VRAM  5034 MiB,        GTT     0 MiB
                      Evicted: VRAM  5033 MiB

raw

pos:    0
flags:  02100002
mnt_id: 25
ino:    380
drm-driver:     amdgpu
drm-client-id:  56
drm-pdev:       0000:08:00.0
pasid:  32791
drm-memory-vram:        308 KiB
drm-memory-gtt:         5154844 KiB
drm-memory-cpu:         0 KiB
amd-memory-visible-vram:        308 KiB
amd-evicted-vram:       5154580 KiB
amd-evicted-visible-vram:       0 KiB
amd-requested-vram:     5154888 KiB
amd-requested-visible-vram:     264 KiB
amd-requested-gtt:      264 KiB
drm-engine-gfx: 32869503372 ns

[thesunexpress]

I have an eGPU here. Which usually works great, seemingly until a game overallocates VRAM. Sometimes the amdgpu+Mesa seem to do a good job to swap from VRAM to RAM, sometimes not.

It would be great to have a way to check how much the Thunderbolt 3 port is saturated, maybe in radeontop? So that I would know if this is the bottleneck in a specific situation. Right now I see no way to check this on Linux (usbmon does not work for my USB4 USB-C port).

Don't know what the output is for usbtop (from GH aguinet/usbtop) in the Linux world, but for FreeBSD this little app reports frames & data throughput per device. Apply a bit of math & it should give you an idea if that's anywhere near what Thunderbolt 3 specs provide.