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In order to debug kernel or use tools like stap (https://en.wikipedia.org/wiki/SystemTap) kernel must be compiled with full debugging information included - namely option CONFIG_DEBUG_INFO has to be enabled.
I was wondering how does it impact system performance when kernel is compiled with debug options?
I have measured the cpu performance on such kernel with linpack benchmark but it didn't change. What about eg. syscall's speed or other things I don't know about?
Some extra debug information like getting the call stack and some other things like that that are needed by gdb for debugging will be enabled.
This will have slight impact in the performance. But you will see this mainly by using the tools using which most of the code runs in the kernel space. e.g. check the speed of a file copy, creating multiple threads and switching between then etc.
Linpack is a software library (user space) for performing numerical linear algebra. Mostly this makes very minimal or no system calls. i.e. minimal interaction with the kernel. Thereby you don't see much change in performance measured using Linpack.
