Linux 7.3 improves performance when running out of vRAM
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Linux 7.3 improves performance when running out of vRAM
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Re: Linux 7.3 improves performance when running out of vRAM
#2[dead]
Re: Linux 7.3 improves performance when running out of vRAM
#3Well written and very informative. I am glad we have these enthusiastic people around for Linux kernel development!
Re: Linux 7.3 improves performance when running out of vRAM
#4Well written and very informative. I am glad we have these enthusiastic people around for Linux kernel development!
Enthusiasm seems proportional to the number of exclamation marks (28)! (:
Re: Linux 7.3 improves performance when running out of vRAM
#5This is a nice blog and it makes sense to me now. As a gamer and linux user myself, I've previously had to do tweaks and go-arounds without really understanding what was going on behind the scenes. :)
Re: Linux 7.3 improves performance when running out of vRAM
#6Great writeup, gpuvis looks particularly interesting and glad the kernel is providing tracepoints for performance events.
> Not only does the display hardware like scanned-out images to be in VRAM, it also completely skips past the GPU’s virtual memory architecture and works with physical addresses exclusively.
Well there's your problem. Only so smart your memory management can be when you have to pay the cost of doing it manually. Although presumably this only applies to a small fraction of the VRAM?
Re: Linux 7.3 improves performance when running out of vRAM
#7I'll be the one to ask the obvious question:
What does this mean for compute workloads? Specifically, LLM inference.
Does it mean anything at all, or is this purely a games-thing?
Re: Linux 7.3 improves performance when running out of vRAM
#8I'll be the one to ask the obvious question: What does this mean for compute workloads? Specifically, LLM inference. Does it mean anything at all, or is this purely a games-thing?
I doubt it makes much of a difference, and you can always manually manage what data lives in the GPU when if you 100% have to overcommit. Games have a much larger and more diverse set of objects in the VRAM, and their usage is less predictable, so manual scheduling of the memory is infeasible typically.
Re: Linux 7.3 improves performance when running out of vRAM
#9Great writeup, gpuvis looks particularly interesting and glad the kernel is providing tracepoints for performance events. > Not only does the display hardware like scanned-out images to be in VRAM, it also completely skips past the GPU’s virtual memory architecture and works with physical addresses exclusively. Well there's your problem. Only so smart your memory management can be when you have to pay the cost of doi…
> Although presumably this only applies to a small fraction of the VRAM?
They did mention they saw 4GiB of eviction for a single 32MiB scan out image.
So while I would call the image allocation small, it seems to cause an avalanche of evictions. Amplified by the fact that each frame has one of these images, though I expect subsequent frames might have a better chance of already fitting into evicted space.
What I don't exactly understand is: doesn't it make sense to always reserve the contiguous physical memory for this case and not allow anything else to be put in it?
Re: Linux 7.3 improves performance when running out of vRAM
#10Great article. I find that I learn something every time I read a post about linux kernel work.
I guess an LRU with priority would handle VRAM for games pretty decently without going getting too application specific.
What about VRAM to Disk specifically NVME, would direct to disk be feasible for large workloads, I know it is used for streaming in assets directly via. PCIE, but i wonder how the performance would be on compute workloads running with NVME as a swap for GPU VRAM.