perf build: Fix single target build dependency check

Currently if we build a single target like:

  $ touch util/map.c && make util/map.o

It will not rebuild util/map.o if it already exists and util/map.c is
modified.

The reason is that the top-level 'Makefile' processes util/map.o as an
implicit rule and if util/map.o exists make considers the 'util/map.o'
target as done and will not nest into Makefile.perf.

Adding FORCE for '%', because that's what we want to nest into
Makefile.perf for any target.

Adding Makefile into phony targets, because make tries to rebuild it and
it's also resolved as '%' target.

Signed-off-by: Jiri Olsa <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Lukas Wunner <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions