parca-agent

I find this surprising! Was this for off the shelf applications or some custom binaries? We see DWARF expressions such as `DW_CFA_def_cfa_expression` on the regular. See the "Test Plan" section and commit messages of the PR that introduced support for this particular opcode, as well as the simple executable that shows this opcode [0] and its printed unwind table [1] [0]: https://github.com/parca-dev/parca-agent/pull/1058 [1]: https://github.com/parca-dev/testdata/blob/7f9206570a743206f...

Author here! This project looks interesting and as you mention it seems conceptually similar! I would agree with that quote, generally speaking, but I think it really depends on a binary to binary basis. Some binaries outsource most of the work to dynamic libraries. Unfortunately, DWARF expressions are typically emitted for these program counter ranges, so it's desirable to at least implement a subset of expressions [0]. Even if that's not the case, we want to produce profiles that are as accurate as possible :) You are totally right, they were discussing kernel stacks where stakes are higher as it needs to work perfectly, otherwise kernel live patching would not reliably work, among others. The kernel has now some unwind table format, that can be used in x86_64, called ORC [1]. That being said the parser for DWARF would still have to liv

repo: https://github.com/parca-dev/parca-agent