On Mon, 2024-07-22 at 17:57 -0700, Eduard Zingerman wrote: > On Mon, 2024-07-22 at 17:39 -0700, Alexei Starovoitov wrote: > > [...] > > > Andrii, Ihor, > > > > not sure what happened, but 'make clean' now takes forever. > > Pls take a look. > > It happens under certain conditions, here is a scenario that behaves > badly for me: > - two branches: > - 'master' at cca09a371fa7 > - 'tmp' with [0] applied on top of master > - Steps to repro: > > # cd selftests directory > $ git checkout tmp > $ git clean -xfd . # be careful > $ make -j test_progs > $ git checkout master > $ make clean > > After which output looks as follows: > > CLNG-BPF [test_maps] access_map_in_map.bpf.o > GEN-SKEL [test_progs] access_map_in_map.skel.h > CLNG-BPF [test_maps] arena_atomics.bpf.o > GEN-SKEL [test_progs] arena_atomics.skel.h > ... > > [0] https://lore.kernel.org/bpf/20240719110059.797546-1-xukuohai@xxxxxxxxxxxxxxx/ Here is a funny part. The switch from 'tmp' to 'master' touches a number of prog_tests/*.c files. The output of 'make --debug=basic clean' is: Reading makefiles... Updating makefiles.... CLNG-BPF [test_maps] access_map_in_map.bpf.o GEN-SKEL [test_progs] access_map_in_map.skel.h There are .test.d files after test_progs build for tmp. Because of the include directive: include $(wildcard $(TRUNNER_TEST_OBJS:.o=.d)) and a dependency: $(TRUNNER_TEST_OBJS:.o=.d): $(TRUNNER_OUTPUT)/%.test.d: \ $(TRUNNER_TESTS_DIR)/%.c \ ... make goes ahead and detects that these .test.d files are now outdated. So, before executing 'clean' recipe it executes recipes to update .test.d files.
