Meeting with Larry, Ryan, Matt, Ric, cpo on Feb. 9, 2024
To address concerns about LCLS-II HE large area detectors
run a different driver (same github repo as datadev): requires "Quadro" ability. RTX A5000 (in drp-srcf-cmpNNN) seems to have this ability.
additional dma engine needs slightly different dma engine
"metadata" word write triggers gpu
- two physical addresses: destination for data and mailbox address
which gpu would wait on
TID driver uses "GPUDirect" to move data directly to GPU memory over pcie
does a cpu need to be involved in the path? unclear. maybe a little.
multiple gpus? might need firmware development. currently 1-to-1. Matt points out that if GPUs support 30GB/s of SZ compression that matches about what one KCU1500/C1100 could do, so maybe have to have 1-to-1.
have to disable something in linux kernel to i2o or p2p that
allow the direct pci computation
include in makefile the path to nvidia drivers
https://docs.nvidia.com/cuda/gpudirect-rdma/index.html
http://mug.mvapich.cse.ohio-state.edu/static/media/mug/presentations/2016/MUG16_GPU_tutorial_V5.pdf
ryan/larry will resurrect the driver
cpo try to install kcu in our gpu nodes
cpo gets account number
research nvlink: direct to gpu, avoids pcie, still a closed protocol?)