perf build: Fix python/perf.so library's name

Since Python 3.3 extensions have a suffix encoding platform and
version information. For example, the perf extension was previously
perf.so but now maybe perf.cpython-310-x86_64-linux-gnu.so. Compute
the extension using Python and then use this in the target name. Doing
this avoids the "perf.so" target always being rebuilt.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Eelco Chaudron <echaudro@redhat.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Shaomin Deng <dengshaomin@cdjrlc.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Timothy Hayes <timothy.hayes@arm.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221213232651.1269909-2-irogers@google.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Makefile.config

@@ -871,6 +871,7 @@ define disable-python_code
   NO_LIBPYTHON := 1
 endef
 
+PYTHON_EXTENSION_SUFFIX := '.so'
 ifdef NO_LIBPYTHON
   $(call disable-python,Python support disabled by user)
 else
@@ -889,7 +890,8 @@ else
       else
          LDFLAGS += $(PYTHON_EMBED_LDFLAGS)
          EXTLIBS += $(PYTHON_EMBED_LIBADD)
-         LANG_BINDINGS += $(obj-perf)python/perf.so
+         PYTHON_EXTENSION_SUFFIX := $(shell $(PYTHON) -c 'from importlib import machinery; print(machinery.EXTENSION_SUFFIXES[0])')
+         LANG_BINDINGS += $(obj-perf)python/perf$(PYTHON_EXTENSION_SUFFIX)
          CFLAGS += -DHAVE_LIBPYTHON_SUPPORT
          $(call detected,CONFIG_LIBPYTHON)
       endif

tools/perf/Makefile.perf

@@ -647,7 +647,7 @@ all: shell_compatibility_test $(ALL_PROGRAMS) $(LANG_BINDINGS) $(OTHER_PROGRAMS)
 # Create python binding output directory if not already present
 _dummy := $(shell [ -d '$(OUTPUT)python' ] || mkdir -p '$(OUTPUT)python')
 
-$(OUTPUT)python/perf.so: $(PYTHON_EXT_SRCS) $(PYTHON_EXT_DEPS) $(LIBPERF)
+$(OUTPUT)python/perf$(PYTHON_EXTENSION_SUFFIX): $(PYTHON_EXT_SRCS) $(PYTHON_EXT_DEPS) $(LIBPERF)
 	$(QUIET_GEN)LDSHARED="$(CC) -pthread -shared" \
         CFLAGS='$(CFLAGS)' LDFLAGS='$(LDFLAGS)' \
 	  $(PYTHON_WORD) util/setup.py \