Perf Support For 2,048 CPU Cores Is Becoming Not Enough - Patches Bump Kernel Limit

[phoronix]

Phoronix: Perf Support For 2,048 CPU Cores Is Becoming Not Enough - Patches Bump Kernel Limit

Currently the Linux kernel's "perf" performance monitoring subsystem has a limit on 2,048 CPU cores for its CPU map that is set by the MAX_NR_CPUS value. But that's becoming not enough in today's high core count era that patches are looking to raise it to a 4,096 CPU core limit by default...

https://www.phoronix.com/news/Perf-Support-2048-To-4096-Cores

[chuckula]

I'd be a lot more interested in GPUs if their cores could be addressed transparently in the kernel just like a CPU core. That would also definitely require a bump in the max core count.

[YCbCr]

Obligatory xkcd: https://www.xkcd.com/619/

[espi]

I'd be a lot more interested in GPUs if their cores could be addressed transparently in the kernel just like a CPU core. That would also definitely require a bump in the max core count.

It depends on what is interpreted as a "core". A CUDA core (Nvidia) or Shader core (AMD) are arguably not cores. If you consider Streaming Multiprocessor/Workgroup Processors as cores then modern GPUs don't have that many, an RTX 4090 "only" has 128 SMs for example.

[Gamer1227]

Obligatory xkcd: https://www.xkcd.com/619/

The main market for Linux is servers, so it makes sense.

But we finally reached the 4096 cores mark like in the comic. xD

[Gamer1227]

I'd be a lot more interested in GPUs if their cores could be addressed transparently in the kernel just like a CPU core. That would also definitely require a bump in the max core count.

Like the guy said above, a cuda core (NVIDIA) is not comparable to a CPU core, since they do not have indepedent hardware for control, in a SM, 32 CUDA cores are running the same instructions, just in different data.

And you cant have a GPU with less than 128 CUDA cores, since that is what a SM have, it would be like a CPU with a half core.

That is the single instruction multiple threads (SIMT) model, wich is necessary for GPUs to scale, since it reduces the amount of control hardware necessary, leaving more space and power for execution hardware.

[Britoid]

The new minimum specifications to run electron apps

[arteast]

So, someone has a machine with over 2048 cores in it, and their application still runs too slow (I mean, why else would they run perf)? "Just throw more hardware at it" problem solving method has gone terribly wrong on this one.</joke>

[numasan]

32 sockets?! How big is that motherboard?

[oibaf]

The main market for Linux is servers, so it makes sense.

But we finally reached the 4096 cores mark like in the comic. xD

We also reached the mark that Flash was finally deprecated for good 😋