[PATCH v5 00/17] Add static_call()

[Peter Zijlstra]

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