When building with C=2, sparse makes note of a number of things:

  arch/x86/events/intel/rapl.c:637:30: warning: symbol 'rapl_attr_update' was not declared. Should it be static?
  arch/x86/events/intel/cstate.c:449:30: warning: symbol 'core_attr_update' was not declared. Should it be static?
  arch/x86/events/intel/cstate.c:457:30: warning: symbol 'pkg_attr_update' was not declared. Should it be static?
  arch/x86/events/msr.c:170:30: warning: symbol 'attr_update' was not declared. Should it be static?
  arch/x86/events/intel/lbr.c:276:1: warning: symbol 'lbr_from_quirk_key' was not declared. Should it be static?

And they can all indeed be static.
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/128059.1565286242@turing-policeSigned-off-by: Ingo Molnar <mingo@kernel.org>