Wouldn't the Nsight Systems suite provide coverage here? Are the tricky cases difficult to debug with the standard CUDA tooling stack?
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ddelnano
https://twitter.com/@ddelnano
Does anyone know how their KV cache sync mechanism compares to newer P2P communication layers like nixl, uccl p2p, etc.?
The authors mention that NCCL and Ray initialization were too slow (see quote below), but from the description it sounds like they’ve reimplemented a layer that’s increasingly being standardized by frameworks like nixl and uccl.
Distributed executor: Inference engines support model parallelism via distributed executors (e.g., Ray [32] and NCCL [9]), whose initialization takes tens of seconds.
What kind of NCCL testing are you thinking about? Always curious what’s hardest to validate in people’s setups.
For Linux kernel dev, I found Linux Kernel Programming: A Comprehensive Guide to Kernel Internals to be a really helpful resource. For eBPF, the early chapters of Brendan Gregg’s BPF Performance Tools gave me the context I needed to get started.
From there, what’s helped me most is a cycle of reading new material, building prototypes and exploring how an open source system solves similar problems. I've definitely hit that wall as systems programming can get confusing fast.
I’ve also noticed that I sometimes get stuck trying to make something perfect before I’ve even started experimenting. Forcing myself to build the lowest-effort version of an idea has been surprisingly productive. Debugging things that don’t work is frustrating, but that failure often reveals insights I wouldn’t have discovered if I were overanalyzing.
You’ve probably seen some of these resources already, but just sharing in case any of it’s useful. I work with eBPF full-time and had many similar challenges along the way, but recommend jumping back in when you have the time.
For kernel dev and eBPF, what kinds of resources or tutorials have you tried in the past? Have you ever tried building something small or contributing to an existing project?
Curious to hear what hurdles you ran into.
Even if you have experience with DWARF, I think you will learn something new from the book.
I work on CNCF Pixie, which uses DWARF for eBPF uprobes and dynamic instrumentation. While I understood how our project uses DWARF, the book made many details much clearer for me.
It covers version 4, but it explains differences with v5 as they come up.
Also second that the book is a fantastic read. I work in the eBPF profiling space (on CNCF Pixie) and this has helped me understand DWARF concepts that I previously took at face value in our project's implementation.
The approach you describe above is common for similar projects:
- Pixie (https://px.dev) -- which I contribute to
- Beyla (https://github.com/grafana/beyla)
- Coroot (https://github.com/coroot/coroot)
If you are interested in the details and how the strategy for this tracing has evolved, you can learn more in this blog (https://blog.px.dev/ebpf-tls-tracing-past-present-future/).
Disclaimer: I'm a maintainer of the project
Pixie [1] is a similar project and offers the self hosted model you are looking for.
We also support 11 application protocols [2] with TLS handshake tracing and MQTT support coming soon (encrypted traffic tracing has been supported for a long time).
[1] https://px.dev
Disclaimer: I'm a maintainer of the project
Pixie (https://px.dev) can be installed in under 5 mins and gives this level of visibility across all applications. No need to change your application (wrap in `subtrace run`) to get instant visibility.
We also support 11 application protocols (https://docs.px.dev/reference/datatables/) with TLS handshake tracing and MQTT support coming soon (encrypted traffic tracing has been supported for a long time).
Definitely agree. As I've looked into instrumentation/tracing, it has helped me more fearlessly look at the kernel. Ftrace is another tool that's helped me level up as well (https://blog.px.dev/ebpf-probes-and-you/)
Yep, that's correct. It uses eBPF upprobes to attach to the SSL_write/SSL_read functions.
Author here :). Happy to answer any questions on this TLS tracing stuff.