Matt MattAlp

How to Enable Intel PT (Processor Trace) in QEMU-KVM VMs

Caution

Intel PT virtualization is BROKEN, as it has multiple fatal flaws, several which put the host at risk. Use at your own risk.

This guide will most likely become obsolete once the feature will be removed from the various linux distros. For more info check out KVM: VMX: Mark Intel PT virtualization as BROKEN and CVE-2024-53135

This script sets KVM Processor Trace feature in host-guest mode enabling VMs to use intel-pt

V8

V8 is Google’s open source high-performance JavaScript and WebAssembly engine, written in C++. It is used in Chrome and in Node.js, among others. It implements ECMAScript and WebAssembly, and runs on Windows 7 or later, macOS 10.12+, and Linux systems that use x64, IA-32, ARM, or MIPS processors. V8 can run standalone, or can be embedded into any C++ application.

SpiderMonkey

SpiderMonkey is Mozilla’s JavaScript and WebAssembly Engine, used in Firefox, Servo and various other projects. It is written in C++, Rust and JavaScript. You can embed it into C++ and Rust projects, and it can be run as a stand-alone shell. It can also be [compiled](https://bytecodealliance.org/articles/making-javascript-run-fast-on

immutable = deeply frozen

Immutable classes

Immutable core classes

TrueClass
FalseClass
NilClass
Integer

let's say you have a C++ project in Nix that you want to work on with CLion so that the nix dependencies are available.

create a .nix utility directory in your project directory.
put the below nix-run.sh and nix-cmake.sh in the .nix directory.
in the .nix directory create symlinks for make, gcc, g++ - and maybe more tools, that need to have the nix dependencies and build tools available - and point them to nix-run.sh
then, in Settings -> Build, Execution, Deployment -> Toolchains set CMake to the path to nix-cmake.sh and point all other build tools to the symlinks you've created.

A half-hour to learn Zig

This is inspired by https://fasterthanli.me/blog/2020/a-half-hour-to-learn-rust/

Basics

the command zig run my_code.zig will compile and immediately run your Zig program. Each of these cells contains a zig program that you can try to run (some of them contain compile-time errors that you can comment out to play with)

install and run AWS linux 2 on home computer as a virtual machine

These instructions are tailored for KVM and virt-manager specifically .

Detailed Instructions are here : https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/amazon-linux-2-virtual-machine.html ( for VMWare and VirtualBox and Hyoer-V in addiation to KVM )

Instructions sample configs and cloud-init files for on on-premises images: https://cdn.amazonlinux.com/os-images/2.0.20201111.0/

Falsehoods that Ethereum programmers believe

I recently stumbled upon Falsehoods programmers believe about time zones, which got a good laugh out of me. It reminded me of other great lists of falsehoods, such as about names or time, and made me look for an equivalent for Ethereum. Having found none, here is my humble contribution to this set.

About Gas

Calling `estimateGas` will return the gas required by my transaction

Calling estimateGas will return the gas that your transaction would require if it were mined now. The current state of the chain may be very different to the state in which your tx will get mined. So when your tx i

	import torch
	import torch._inductor.config
	import time

	torch._inductor.config.triton.cudagraphs = False
	torch.set_float32_matmul_precision('high')

	def bench(f, name=None, iters=100, warmup=5, display=True, profile=False):
	for _ in range(warmup):
	f()

	defaults write com.apple.Dock appswitcher-all-displays -bool true
	killall Dock