5 ms·
Clearly not, which is exactly why kernel bypass is such a huge red flag: it's only possible (rather, useful) if you aren't doing anything sensible with the data
by revelation 11y ago
Clearly not, which is exactly why kernel bypass is such a huge red flag: it's only possible (rather, useful) if you aren't doing anything sensible with the data anyway, or the kernel overhead would be tiny compared to the processing.
Use the right tool for the job and don't funnel network data through your instruction pipeline. When they realized that for memory, they called it "DMA", and when graphics was scaling up, we created the GPU.
- p1esk 11y agoWhat would be "the right tool for the job" here? If no processing is needed, why is the kernel bypass is "a huge red flag"?
- detaro 11y agoThey probably could have used cards/systems capable of RDMA instead, but I don't see what's wrong with their approach.
- greglindahl 11y agoThe networks used by supercomputers have have kernel bypass with DMA for more than a decade... and they do a lot of processing on the data, too. Check out Infiniband and Intel's Omni-Path for modern examples. Or the Cray T3E (1995), which had an excellent network with a user-level DMA engine that only did 8- or 64-byte transfers.
- ryanlol 11y agoAre you kidding me? How could not bypassing the kernel POSSIBLY be better here? It's infinitely harder for kernel devs to optimize these scenarios than for userland devs.