[llvm] [BOLT] Add writing support for Linux kernel ORC (PR #80950)

[Maksim Panchenko via llvm-commits]

maksfb wrote:

> Hi @maksfb Thanks for your great work!
> 
> I'm newbie here and have a naive question: this is designed to work with the _sampling_ mode, not _instrumentation_ mode. Right? Also may I ask where I can find the steps of trying and reproducing some of the BOLT-kernel results? Much appreciated!

Hi @whentojump, in theory, it shouldn't matter how the profile for the kernel was collected. At the moment though, we don't have instrumentation support, so you have to use sampling.

For now, not all patches are in the main branch. Originally, there will be a constraint on the kernel config and version than are supported by BOLT. Once I upstream the first set, I'll publish the instructions.


https://github.com/llvm/llvm-project/pull/80950