Commit e310718d authored Nov 14, 2013 by Ingo Molnar

tools/perf/build: Fix feature-libunwind-debug-frame handling



Set feature-libunwind-debug-frame. We don't want it in
CORE_FEATURE_TESTS because it's not the generic case, but we
need to set it in the !feature-libunwind case.

Also, because x86 distributions typically don't have
dwarf_find_debug_frame() unwinding method:

  test-libunwind-debug-frame.c:(.text+0x31): undefined reference to `_Ux86_64_dwarf_find_debug_frame'

Restrict this new API to ARM for the time being.

With this patch test-all.c works again, so repeat perf builds
are  fast again:

  comet:~/tip> perf stat --null --repeat 5 make -C tools/perf/
  [...]

       0,452899660 seconds time elapsed                                          ( +-  0,11% )

While with before it was:

  comet:~/tip> perf stat --null --repeat 5 make -C tools/perf/
  [...]

       1,674001829 seconds time elapsed                                          ( +-  0,16% )

[ Includes fix to config/feature-checks/Makefile from Will Deacon. ]

Tested-by: Will Deacon <will.deacon@arm.com>
Tested-by: Jean Pihet <jean.pihet@linaro.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-scsoctqzmou3rpkixCHezy9e@git.kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent bb4c5500

tools/perf/config/Makefile

+8 −2

Original line number	Diff line number	Diff line
		@@ -329,10 +329,16 @@ ifndef NO_LIBUNWIND
		msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 1.1);
		NO_LIBUNWIND := 1
		else
		ifeq ($(ARCH),arm)
		$(call feature_check,libunwind-debug-frame)
		ifneq ($(feature-libunwind-debug-frame), 1)
		msg := $(warning No debug_frame support found in libunwind);
		CFLAGS += -DNO_LIBUNWIND_DEBUG_FRAME
		endif
		else
		# non-ARM has no dwarf_find_debug_frame() function:
		CFLAGS += -DNO_LIBUNWIND_DEBUG_FRAME
		endif
		endif
		endif

tools/perf/config/feature-checks/Makefile

+3 −0

Original line number	Diff line number	Diff line
		@@ -76,6 +76,9 @@ test-libnuma:
		test-libunwind:
		$(BUILD) $(LIBUNWIND_LIBS) -lelf

		test-libunwind-debug-frame:
		$(BUILD) $(LIBUNWIND_LIBS) -lelf

		test-libaudit:
		$(BUILD) -laudit

tools/perf/config/feature-checks/test-all.c

+0 −4

Original line number	Diff line number	Diff line
		@@ -49,10 +49,6 @@
		# include "test-libunwind.c"
		#undef main

		#define main main_test_libunwind_debug_frame
		# include "test-libunwind-debug-frame.c"
		#undef main

		#define main main_test_libaudit
		# include "test-libaudit.c"
		#undef main