> Am 16.07.2019 um 19:49 schrieb Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>: > > On Mon, Jul 15, 2019 at 3:22 PM Daniel Borkmann <daniel@xxxxxxxxxxxxx> wrote: >> >> On 7/12/19 3:56 PM, Ilya Leoshkevich wrote: >>> When directories are used as prerequisites in Makefiles, they can cause >>> a lot of unnecessary rebuilds, because a directory is considered changed >>> whenever a file in this directory is added, removed or modified. >>> >>> If the only thing a target is interested in is the existence of the >>> directory it depends on, which is the case for selftests/bpf, this >>> directory should be specified as an order-only prerequisite: it would >>> still be created in case it does not exist, but it would not trigger a >>> rebuild of a target in case it's considered changed. >>> >>> Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx> >> >> Applied, thanks! > > Hi Ilya, > > this commit breaks map_tests. > To reproduce: > rm map_tests/tests.h > make > tests.h will not be regenerated. > Please provide a fix asap. > We cannot ship bpf tree with such failure. Hi Alexei, Sorry about this! I actually had the following in my local tree: diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index f1f2b82b8fb8..95795cf5805c 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -231,7 +231,7 @@ ifeq ($(DWARF2BTF),y) endif PROG_TESTS_H := $(OUTPUT)/prog_tests/tests.h -test_progs.c: $(PROG_TESTS_H) +$(OUTPUT)/test_progs: $(PROG_TESTS_H) $(OUTPUT)/test_progs: CFLAGS += $(TEST_PROGS_CFLAGS) $(OUTPUT)/test_progs: prog_tests/*.c @@ -258,7 +258,7 @@ MAP_TESTS_DIR = $(OUTPUT)/map_tests $(MAP_TESTS_DIR): <------>mkdir -p $@ MAP_TESTS_H := $(MAP_TESTS_DIR)/tests.h -test_maps.c: $(MAP_TESTS_H) +$(OUTPUT)/test_maps: $(MAP_TESTS_H) $(OUTPUT)/test_maps: CFLAGS += $(TEST_MAPS_CFLAGS) MAP_TESTS_FILES := $(wildcard map_tests/*.c) $(MAP_TESTS_H): $(MAP_TESTS_FILES) | $(MAP_TESTS_DIR) @@ -275,7 +275,7 @@ $(MAP_TESTS_H): $(MAP_TESTS_FILES) | $(MAP_TESTS_DIR) <------><------> ) > $(MAP_TESTS_H)) VERIFIER_TESTS_H := $(OUTPUT)/verifier/tests.h -test_verifier.c: $(VERIFIER_TESTS_H) +$(OUTPUT)/test_verifier: $(VERIFIER_TESTS_H) $(OUTPUT)/test_verifier: CFLAGS += $(TEST_VERIFIER_CFLAGS) VERIFIER_TESTS_DIR = $(OUTPUT)/verifier but did not realise that this is a pre-requisite for my directories change. I should have tested it separately, then I would have noticed. Andrii, Thanks for helping out and providing the fix! Best regards, Ilya
