[PATCH v5 00/17] Add static_call()

Peter Zijlstra
2020-06-24T15:52:40Z

Hi all,

Hopefully for the last time...

static_call(), is the idea of static_branch() applied to indirect function
calls. Remove a data load (indirection) by modifying the text.

The inline implementation still relies on objtool to generate the
.static_call_sites section, mostly because this is a natural place for x86_64
and works for both GCC and LLVM. Other architectures can pick other means
if/when they implement the inline patching. The out-of-line (aka. trampoline)
variant doesn't require this.

Patches go on top of tip/objtool/core + tip/perf/core

Patches can also be found here:

git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git x86/static_call

Changes since the last time:

- Better documentation
- More consistent macro names
- Changed key prefix
- Folded trampoline definitions
- Renamed DEFINE_STATIC_COND_CALL / DEFINE_STATIC_CALL_NULL