Computer science pioneer and United States Navy rear admiral Grace Hopper was born #OTD in 1906.

As far as I’m aware, she is the only person who has both a supercomputer and a US Navy destroyer named after her.

Image: Computer History Museum

Shared by my Daughter
"I need privacy, not because my actions are questionable, but because your judgement and intentions are"

In response to "if you have nothing to hide you have nothing to fear"

Back in November I did a presentation at the Driving IT conference in Copenhagen, where I tried to make the case that we should all focus more on latency and less on throughput when building systems and applications.

The talk is really channelling Stuart Cheshire's classic rant (from 1996!), from which I also shamelessly stole the title: "It's the Latency, Stupid!"

Anyway, the video is now finally online, if you'd care to have a listen: https://videos.ida.dk/id/1_47l9o3qn

Okay, so let me tell you about my doorbell, from a #networking perspective.

When you push the button by the door, it sends a message over the #zigbee wireless mesh network in my house. It probably goes through a few hops, getting relayed along the way by the various Zigbee light switches and "smart outlets" I have.

Once it makes it to my utility closet, it's received by a Zigbee-to-USB dongle, through a USB hub (a simple tree network) plugged into an SFF PC. From there, it gets fed into zigbee2mqtt, which, as the name implies, publishes it to my local #mqtt broker.

The mqtt broker is in the small #kubernetes cluster of #raspberrypi nodes I run in my utility closet. To get in (via a couple of #ethernet switch hops), it goes through #metallb, which is basically a proxy-ARP type service that advertises the IP address for the mqtt endpoint to the rest of my network, then passes the traffic to the appropriate container via a #linux veth device.

I have #HomeAssistant, running in the same Kubernetes cluster, subscribed to these events. Within Kubernetes, the message goes through the CNI plugin that I use, #flannel. If the message has to pass between hosts, Flannel encapsulates it in VXLAN, so that it can be directed to the correct veth on the destination host.

Because I like #NodeRed for automation tasks more than HomeAssistant, your press of the doorbell takes another hop within the Kubernetes cluster (via a REST call) so that NodeRed can decide whether it's within the time of day I want the doorbell to ring, etc. If we're all good, NodeRed publishes an mqtt message (more VXLANs, veths, etc.)

(Oh and it also sends a notification to my phone, which means another trip through the HomeAssistant container, and leaving my home network involves another soup of acronyms including VLANs, PoE, QoS, PPPoE, NAT or IPv6, DoH, and GPON. And maybe it goes over 5G depending on where my phone is.)

Of course something's got to actually make the "ding dong" sound, and that's another Raspberry Pi that sits on top of my grandmother clock. So to get *there* the message hops through a couple Ethernet switches and my home WiFi, where it gets received by a little custom daemon I wrote that plays the sound via an attached #HiFiBerry board. Oh but wait! We're not quite done with networking, because the sound gets played through PulseAudio, which is done through a UNIX domain socket.

SO ANYWAY, that's why my doorbell rarely works and why you've been standing outside in the snow for five minutes.

Without internet connectivity since yesterday afternoon. Looks like my upstream ISP had a largish equipment failure which took them all night to recover from. This morning I have a physical connection (I get LLDP packets from a device at the other end) but my BGP peer is MIA.

Spent an hour in the helpdesk queue and all they could tell me was "we'll put it in the queue for our technician". Ugh.

Do I know anyone who can provide me with a temporary BGP session over a tunnel (and reannounce my addresses to their upstream)?

Did an interview for a Danish newspaper about #bufferbloat and internet connectivity. The article turned out pretty well, I think! It's in Danish and unfortunately paywalled, but just in case I know anyone with an account, here's the link (article by @LauridsHovgard):

https://ing.dk/artikel/daarlig-koekultur-din-router-flaskehals-din-netforbindelse-263272

Upgraded my phone to #LineageOS 19 (which is based on #Android 12). The UI runs noticeably smoother and the updated theme is pretty nice as well!

Now I just have to reinstate all the workarounds for the various apps that refuse to run if they think my phone is rooted 🤔🙄

If you have a kernel.org account, you can set your webfinger by using:

ssh git@gitolite.kernel.org social set @your@social.example.foo

This will let people find your fediverse account by searching for “@yourusername@kernel.org“.

Use “social help“ to see other commands.

Proper documentation forthcoming and will be on korg.docs.kernel.org once done.

Which browser do you use?
Thanks for any boosts! I wanna know!

Installed mastodon.el and am now able to toot from within #emacs itself - very
neat, and seems to work quite well!

As always, with Emacs, the biggest problem is the blocking network requests;
pining for multithreading...

I keep seeing lots of long-time #fediverse users saying 'don't favourite posts it does nothing' but actually when you favourite my posts it makes me smile and I'm sure I'm not the only one.

Right, so I guess it's time for a slightly belated #introduction

I'm a Linux kernel hacker at Red Hat, working on the networking and BPF subsystems. I maintain the sch_cake qdisc and the ath9k WiFi driver, and also dabble in userspace code, most notably the Flent network testing tool and the libxdp library.

I'm also an academic, at least in spirit. Wrote my PhD thesis on fixing #bufferbloat in wired and WiFi networks (get your free copy here: https://bufferbloat-and-beyond.net/ ), and I keep in touch with the academic world through the Red Hat Research programme.

I contribute to FLOSS for both moral and pragmatic reasons: gifting our software to the world is the way we leave this world a bit better than we found it. I consider "proprietary" to be a derogatory term, and loathe the term "IP".

Oh, and I'm the proud "father" of Marvin, the cutest teenage Rhodesian Ridgeback (that's a dog breed)!

Okay, why on earth did I think it was a good idea to start playing with this fediverse thing at such an hour? It's now 2am, and I should definitely set this aside until tomorrow! 😅🙈

Good night everyone!

If you're in the MAINTAINERS file, you can have a social.kernel.org account (but only if you need one -- no need to go around collecting fediverse accounts if you don't intend to use them). Send a request to helpdesk@kernel.org.

Hello, world! 🤓