On Tue, Jun 10, 2025 at 6:03 PM Steven Rostedt <rost...@goodmis.org> wrote: > > > Hi Peter and Ingo, > > This is the first patch series of a set that will make it possible to be able > to use SFrames[1] in the Linux kernel. A quick recap of the motivation for > doing this. > > Currently the only way to get a user space stack trace from a stack > walk (and not just copying large amount of user stack into the kernel > ring buffer) is to use frame pointers. This has a few issues. The biggest > one is that compiling frame pointers into every application and library > has been shown to cause performance overhead. > > Another issue is that the format of the frames may not always be consistent > between different compilers and some architectures (s390) has no defined > format to do a reliable stack walk. The only way to perform user space > profiling on these architectures is to copy the user stack into the kernel > buffer. > > SFrames is now supported in gcc binutils and soon will also be supported > by LLVM. SFrames acts more like ORC, and lives in the ELF executable
Is there any upstream PR or discussion for SFrames support in LLVM to keep track of? > file as its own section. Like ORC it has two tables where the first table > is sorted by instruction pointers (IP) and using the current IP and finding > it's entry in the first table, it will take you to the second table which > will tell you where the return address of the current function is located > and then you can use that address to look it up in the first table to find > the return address of that function, and so on. This performs a user > space stack walk. > [...]
