Simon Willison’s Weblog

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2 items tagged “brendan-gregg”

2024

No More Blue Fridays (via) Brendan Gregg: "In the future, computers will not crash due to bad software updates, even those updates that involve kernel code. In the future, these updates will push eBPF code."

New-to-me things I picked up from this:

  1. eBPF - a technology I had thought was unique to the a Linux kernel - is coming Windows!
  2. A useful mental model to have for eBPF is that it provides a WebAssembly-style sandbox for kernel code.
  3. eBPF doesn't stand for "extended Berkeley Packet Filter" any more - that name greatly understates its capabilities and has been retired. More on that in the eBPF FAQ.
  4. From this Hacker News thread eBPF programs can be analyzed before running despite the halting problem because eBPF only allows verifiably-halting programs to run.

# 22nd July 2024, 6:33 pm / linux, security, windows, webassembly, brendan-gregg

2021

When I was a performance consultant I'd show up to random companies who wanted me to fix their computer performance issues. If they trusted me with a login to their production servers, I could help them a lot quicker. To get that trust I knew which tools looked but didn't touch: Which were observability tools and which were experimental tools. "I'll start with observability tools only" is something I'd say at the start of every engagement.

Brendan Gregg

# 8th June 2021, 7:33 pm / performance, observability, brendan-gregg