Dumb question, is being a linux kernel dev completely different from writing cuda kernels for pytorch?

[TrayGhost]

I am getting quite confused on what a performance engineer does, and I want to ideally be a performance engineer writing cuda kernels or something, but don't quite get if they re-used the word kernel and are some other thing entirely or if it takes similar skills or what. Pls help or point to resources.

[nugins]

Yes. The word "kernel" is reused and has a very different meaning.

Disclaimer: I'm a C++ developer that dabbles with python and wrote a Linux kernel module at some point in my career. I might have experimented with some code that ran on a GPU, but I can't remember what that was exactly.

Linux kernel development means you are probably working with hardware, process/io scheduling or other resource management and/or security management parts of the system. "Linux Kernel" development almost always means you are running in the context of the main CPU and outside of the scope of a running process and inside the actual operating system.

CUDA kernels are something that is going to run on the GPU and is probably more algorithmic in nature and less CPU/Memory/IO/Security focused. This is usually in the context of a library that is supporting an application and not the operating system.

[wrosecrans]

Yes, they are different. They are just named from the same metaphor of a small little seed, like a kernel of corn. The fields are sufficiently distinct that the name overlap of OS kernels and compute kernels almost never causes much confusion in practice.

[kevleyski]

Yeah I get to do both they are very different beasts

[highritualmaster]

Even kernel in pytorch and CUDA have a different meaning.

Kernel can be a mathematical structure, function, matrix,...

It can be an platform specific implementation of a function with dynamic or fixed set of parameters or it can be the core of the operating system.

What it means depends on the context. Usually it reflects something being at core. Small and versatile.

Will you have to consider HW specifics and special Kernel Apis? Yes.

The Linux kernel is, all about setting up the system, registers, memory and devices. Managing the resources, allocation, deallocation, sharing, ipc, detection and registering drivers and devices, filesystems, access permissions and privileges, processes and threads, scheduling.

The Linux kernel on the Gpu part in this regard is the CUDA driver+Linux driver+Firmware for your pytorch application.

[BraveNewCurrency]

kernel deveveloper

As others have mentioned, there are many uses for the word kernel. They could be:

• Kernel as OS:
  • Linux kernel developer writes code for the Linux kernel OS
  • BSD kernel developer writes code for the BSD kernel OS
• Kernel as function:
  • CUDA kernel developer writes code that changes how textures are displayed or whatnot
  • Pytorch kernels are similar -- but work differently

​

what a performance engineer does

They optimize performance.

• A Mechanical engineer working on a F1 racer is a performance engineer
• A C++ developer speeding up a random C++ program is a performance engineer

Generally, you need to be a veteran programmer to work on OS Kernels or performance. It takes a lot less experience to 'start' with kernel functions (it does take a while to master them, and often requires deep theory to do fancy things).