ulidtko

module LibModule where

greeting = "=== Hello, Cabal! === Module Main speaking ~~~"

ulidtko

Mini-repro for SO question about weird TypeScript error message involving contravariance.

Steps

• git clone git@gist.github.com:408b45c4e7b126fb7c28c69140604546.git test && cd test
• npm ci
• npm run build

ulidtko

#!/usr/bin/env python

"""
Use TOTP secret with RFC6238 algorithm for AWS MFA login.

$AWS_PROFILE is expected to be set, naming a section in ~/.aws/credentials

That same section must also contain 2 extra values for this script:

[my-awesome-shiny-aws-account]

ulidtko

{-# LANGUAGE DataKinds, PolyKinds, TypeFamilies #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE FlexibleInstances, UndecidableInstances #-}
{-# LANGUAGE NoStarIsType #-}
{-# OPTIONS_GHC -Wno-orphans #-}
{-# OPTIONS_GHC -fplugin=Overloaded -fplugin-opt=Overloaded:Symbols #-}
module Main where

import Data.Fixed
import Data.Function (on)

ulidtko

#!/usr/bin/env runhaskell
{- cabal:
build-depends:
  aeson,
  attoparsec,
  attoparsec-aeson,
  base,
  bytestring,
  conduit,
  conduit-aeson,

ulidtko

'use strict';
/* Python-like repr() formatter for JS types, with recursion limit. */
/* Adapted from https://gist.github.com/soapie/6407618 */
function repr(x, max, depth) {
	var ELIDED = "[..]";
	if (depth === undefined) depth = 0;
	if (max === undefined) max = 2;
	if (isPrim(x))
		return showPrim(x);
	if (typeof x === 'function')

ulidtko

#!/usr/bin/env python3
"""
https://gist.github.com/ulidtko/fdd7222bd7e85480fa201614fbc42faf
"""

import os
import subprocess
import sys
from time import sleep
from urllib.error import URLError

ulidtko

#!/usr/bin/env python3
import argparse
import datetime
import sys
import os.path

import boto3
import jinja2

ulidtko

Since ~beginning of May 2022, the following symptom appeared.

After roughly a day of uptime, system exhibits pretty heavy lag: ~1s freeze every couple seconds. Input handling pauses (apart from hw cursor); extremely annoying.

That's on linux-lts 5.15.39-1.

Finding 1: dstat --vm shows exorbitant bursts of minor pagefaults (minpf), 61k per second, which correlate perfectly with the lag. Background level is tens to hundreds.

ulidtko

# Oh come on! It's 2020! Stop freezing on OOM, you *clumsy penguin* !

kernel.sysrq = 244
#            =     128+64+32+16  +4
#              256+128+64+32+16+8+4+2+1
#               ^   ^   ^  ^  ^ ^ ^ ^ ^
#               |   |   |  |  | | | | |
#               |   |   |  |  | | | | |  0 - disable every SysRq function.
#               |   |   |  |  | | | | `- 1 - enable every SysRq function.
#               |   |   |  |  | | | `--- 2 - enable control of console logging level