[RFC PATCH 1/4] objtool: Add --mnop as an option to --mcount

Peter Zijlstra peterz at infradead.org
Wed May 25 21:36:42 AEST 2022


On Tue, May 24, 2022 at 04:01:48PM +0530, Naveen N. Rao wrote:

> We need to know for sure either way. Nop'ing out the _mcount locations at
> boot allows us to discover existing long branch trampolines. If we want to
> avoid it, we need to note down those locations during build time.
> 
> Do you have a different approach in mind?

If you put _mcount in a separate section then the compiler cannot tell
where it is and is forced to always emit a long branch trampoline.

Does that help?


More information about the Linuxppc-dev mailing list