Of course this doesn't even come close to this real C++ symbol from ClickHouse. 17900 bytes!

I'm looking at some outlier profiles and apparently Go function names can look like the following these days. That's 440 bytes!

don’t forget to vote if you can, but haven’t yet

I updated my dmesg_hearbeat kernel module example in rust and it's now easier to build than ever: https://github.com/bobrik/dmesg_heartbeat

On the most recent ubuntu it should build out of the box. If you build your kernel yourself, you might need a single line patch.

#linux #kernel #rust

As always, you can run this easily in Docker.

Here it is showing which timers run in my vm:

docker run --rm -it --privileged --net host -v /sys/kernel/debug:/sys/kernel/debug:ro -v /sys/fs/cgroup:/sys/fs/cgroup:ro ghcr.io/cloudflare/ebpf_exporter:v2.5.0 --config.dir /examples --config.names timers

It's been too long since the last ebpf_exporter release, so I cut v2.5.0 today.

https://github.com/cloudflare/ebpf_exporter/releases/tag/v2.5.0

#ebpfef="/hashtag/ebpf_exporter" class="hover:underline text-blue-600 dark:text-sky-400 no-card-link">#ebpf_exporter #ebpf #bpf #linux #kernel

I ended up trying dnsmasq that suppresses gateway.icloud.com on my home server and pointing Apple TV at it (manually to bypass DoH). One needs to suppress A, AAAA and importantly HTTPS records to make this work.

It reduces traffic 10000x (!), but […]

[Original post on mastodon.ivan.computer]

More blood boiling stuff

Debugging this is absolute pain in the ass.

To add a mitm proxy to inspect traffic, you need to add a profile, which requires switching to wifi. In the end the proxy doesn't work with cryptic Apple specific TLS errors (curl works just fine). It may or […]

[Original post on mastodon.ivan.computer]

My Apple TV has Siri off, but it doesn't stop it from downloading something Siri related in a loop due to a recurring error, burning through 184GiB a month.

Traffic might be cheap for Apple, but xfinity only let's me download 1200GiB before extorting […]

[Original post on mastodon.ivan.computer]

Blood boiling stuff

Fun stuff: #linux #perf can't copy userspace stacks over 64k bytes due to u16 field size limit. You need the stack to do unwinding with dwarf.

I have a #rust program that has a single frame twice as big. It's 3 frames combined into one, but still.

The default stack size to copy in perf is just 8k.

If you use #linux #perf on #rust binaries, I highly recommend you check this out:

* https://github.com/torvalds/linux/commit/c3f8644c21df9b7db97eb70e08e2826368aaafa0

For a decently sized binary (just one!) we observed the following resource consumption on v6.6 and Debian Bookworm:

This somewhat explains the unnatural feeling when going 50mph downhill 🫨