@wolf480pl@mstdn.io
@wolf480pl@mstdn.io avatar

wolf480pl

@wolf480pl@mstdn.io

Sysadmin stuck with k8s,
Linux nerd
Likes The Unix Way
🇬🇧🇵🇱(🇯🇵 a bit)

This profile is from a federated server and may be incomplete. Browse more on the original instance.

wolf480pl, to random
@wolf480pl@mstdn.io avatar

The year is 2023. Most people in developed countries have broadband access to the internet. Long gone are the days of 56k modems and waiting for pictures on a website to load. These days we wait for the text to load.

GossiTheDog, to random
@GossiTheDog@cyberplace.social avatar

Okay, this made me laugh.

wolf480pl,
@wolf480pl@mstdn.io avatar

@GossiTheDog captchas might work for this spam bot, but I wouldn't count on them for the long term.

Outside of fedi, I've seen captcha-solving spambots years ago. Also they took their time, slowly registering sleeper accounts over the span of a year, before using them to send any spam.

niconiconi, to random

"Voltmeter"
look inside
Ammeter and resistor

"Ammeter"
look inside
Voltmeter and resistor

wolf480pl,
@wolf480pl@mstdn.io avatar

@niconiconi
"A/D Converter"
looks inside
D/A Converter and a comparator

wolf480pl, to random
@wolf480pl@mstdn.io avatar

Does anyone know a good alternative to Grafana? one that would give me more control of how graphs are drawn?

Ideally I'd wanr matplotlib-level of control but halfway between that and grafana would still be good...

wolf480pl, to random
@wolf480pl@mstdn.io avatar

Is there a game about running an electric grid?

wolf480pl, to random
@wolf480pl@mstdn.io avatar

> How many different products with different performance do you sell under the same name?
> Nvidia: 2, maybe 3
> SSD manufacturers: oh, you sweet summer child, watch this

wolf480pl, to random
@wolf480pl@mstdn.io avatar

> write code in python
> about to use a format string with four %s-es
> remember that this program is supposed to be fast
> use string concatenation instead, hoping that it will save time on parsing the format string
> observe how it's a small function that does only that
> remember that calling functions in python is slow
> remember that anything you do in python will be slow anyway

why do I waste time thinking about these things?

wolf480pl, to random
@wolf480pl@mstdn.io avatar

Wait, Mediatek driver in the upstream Linux kernel supports hardware offload with flowtables now, in addition to Distributed Switch Architecture?

https://github.com/torvalds/linux/commit/502e84e2382d92654a2ecbc52cdbdb5a11cdcec7

And on some routers it also supports eth<->wifi offload?

https://github.com/torvalds/linux/commit/804775dfc2885e93a0a4b35db1914c2cc25172b5

how cool is that!

wolf480pl, to random
@wolf480pl@mstdn.io avatar

tfw. may've found a bug in nginx...

When an HTTP response has neither transfer-encoding: chunked nor content-length, then it's terminated by EOF / connection closing.

But I'm seeing an nginx choke when upstream sends this type of response. I'm seeing that FIN -> FIN ACK -> ACK sequence with tcpdump, so either kernel fucked up and nginx is not getting an EOF, or nginx fucked up and missed it.

wolf480pl, to random
@wolf480pl@mstdn.io avatar

is it possible to use perf-record to sample based on real time instead of CPU cycles?

So like, instead of "the CPU spent this many cycles in that function", I want "the CPU spent this many microseconds in that function and this many microseconds idling"

hm...

or maybe what I need to know is for how much time a process was blocked on which wait queue?

wolf480pl, to random
@wolf480pl@mstdn.io avatar

I shouldn't be using Discord.
You shouldn't be using Discord.

But for those who do anyway:
When it breaks, you'll have an urge to hit F5. Fight that urge.

wolf480pl, to random
@wolf480pl@mstdn.io avatar

how it started:

cAdvisor is great, it can treat any cgroup, even those created by a systemd unit, as a container, and give me kubernetes-like container metrics on a pure Debian system free of containers! It's even shipped in Debian repos!

how it's going:

Debian ships v0.38.7 which depends on runc 1.0.0-rc92, which has a bug reading disk IO stats from cgroup fs v2. The bug was fixed in runc 1.0.0 (non-rc) but cAdvisor updated straight to 1.0.2 in v0.41.0 but Debian doesn't ship that.

1/

wolf480pl, to random
@wolf480pl@mstdn.io avatar

Regarding the jabber.ru MITM incident, looks like Hugo Landau made a great analysis of the problem and detection/mitigation opportunities:

https://www.devever.net/~hl/xmpp-incident

wolf480pl, to random
@wolf480pl@mstdn.io avatar

Is this a good way to measure small (sub-millivolt) voltages, like from a thermocouple?

The idea is to adjust R1 so that current through the micro-ammeter is zero, which means the voltage on R4, which is 33/100033 of the voltage on the voltmeter, is equal to the voltage on the thermocouple.

wolf480pl, to random
@wolf480pl@mstdn.io avatar

A long time ago I was wondering what the regexes in awk's /regex/{code} are for. Like, why would you need those?

Somewhat later I was wondering why some tools output things like:

Key: <key1>
Foo: <foo of key1>
Bar: <bar of key1>
Key: <key2>
Foo: <foo of key2>
Bar: <bar of key2>

Like, there's no convenient way to parse these in a pipeline!

And then I realized that's what /regexes/ in awk are for.

wolf480pl, to random
@wolf480pl@mstdn.io avatar

my algebra lecturer at 1st year of uni was like

> what we're gonna do here is establish a language, a language with which we'll be able to talk about grand things later on

Then he proceeded on a speedrun a lecture series from zero to category theory. Barely anyone could keep up, and by next year we forgot 80% of it.

At the time I thought he's insane.

Today I just understand he had nobody to nerd out with 😢

wolf480pl, to random
@wolf480pl@mstdn.io avatar

is there a book in which fantasy tropes like blue-glowing magical water or trolls turning into stone turn out to be explainable with modern-day physics?

wolf480pl, to random
@wolf480pl@mstdn.io avatar

hmm is it impossible to push nginx to 100% CPU usage with just one concurrent connection?

chjara, to random
@chjara@akko.wtf avatar

deleted_by_author

    •
    wolf480pl,
    @wolf480pl@mstdn.io avatar

    @lanodan @chjara @nullenvk
    Also, it sucks when new syscalls come out.

    You read their manpage and you're like "wat? why would any process need to do such gross things, other than for exploiting a vuln?" so you naturally want to kill the process when it tries to use it.

    Then it turns out libc uses that syscall.

    Fortunately, in most cases returning ENOSYS makes glibc fall back to the old behaviour.
    Also, sometimes you can get away with ENOENT.

    wolf480pl, to random
    @wolf480pl@mstdn.io avatar

    I find it weird that people now apply the word "enshittification" to anything that's gotten progressively worse with time.

    wolf480pl,
    @wolf480pl@mstdn.io avatar

    But that's still about intentionally making a service worse for the users.

    So either way, if things get shittier over time on their own, without anyone pushing it in that direction to make money, I wouldn't call that enshittification.

    wolf480pl,
    @wolf480pl@mstdn.io avatar

    IOW, websites that shouldn't have existed in the first place started getting worse, revealing the real cost of the service they were providing, and making room for non-VC-funded competition.

    The monopolists were pushing users away and that was a good thing, even if it was painful in the short term.
    2/2

    wolf480pl,
    @wolf480pl@mstdn.io avatar

    AFAIU, the word was coined several months ago, when interest rates went up, throttling the stream of free VC money for startups. Investors started demanding ROI, so VC-funded companies had to suddenly make money.

    As a result, web "platforms" that previously were burning money to maximize userbase, suddenly had to find a way to become profitable. At the expense of userbase.

    So they purposefully made changes hostile to non-paying users.

    1/

    wdtz, to random

    Better handling of integer wraparound in the kernel:
    https://lwn.net/Articles/959189/ - ubsan back in use for the kernel!

    Apparently ubsan use was dropped a while back because of interaction with fwrapv and "false positives", these patches add ways to annotate when it's intentional.

    wolf480pl,
    @wolf480pl@mstdn.io avatar

    @wdtz
    yeah I mean, if a warning has a ton of false-positives, people will ignore the warning.

    Now, for a new codebase it'd make sense to have a strict check and try to add those explicit annotations whenever a new case of false-positive is added.

    But for a new linter / compiler warning for old codebase, I agree with Torvald's approach.

    quad, to random
    @quad@akko.quad.moe avatar

    i've done it

    i've invented encrypted NTP

    wolf480pl,
    @wolf480pl@mstdn.io avatar

    @lanodan @quad oh, so it's like Linux's tracepoints...

    idk I prefer being able to instrument the entry and exit of every non-static function

    novenary, to random
    @novenary@akko.wtf avatar

    NAT is bad and if you disagree you're wrong

    wolf480pl,
    @wolf480pl@mstdn.io avatar

    @lanodan @novenary @tetra
    Also, the primary reason preventing those outside from sending unsolicited packets to hosts behind the NAT is that routers outside don't know where to route the private IPs that are used behind the NAT.

    But if you sit on the same network segment as the NAT box's WAN port, you can send a packet directly to it with private IP as a destination, and it will forward that into the LAN.

    Unless it also has a firewall (it should)

  • All
  • Subscribed
  • Moderated
  • Favorites
  • •
  • JUstTest
  • everett
  • InstantRegret
  • osvaldo12
  • magazineikmin
  • thenastyranch
  • rosin
  • Youngstown
  • mdbf
  • slotface
  • ngwrru68w68
  • tester
  • kavyap
  • DreamBathrooms
  • megavids
  • Durango
  • ethstaker
  • cubers
  • modclub
  • GTA5RPClips
  • tacticalgear
  • Leos
  • khanakhh
  • normalnudes
  • provamag3
  • cisconetworking
  • anitta
  • lostlight
  • All magazines
    •