diff options
| author | Eduard Zingerman <eddyz87@gmail.com> | 2024-12-12 16:32:24 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-12-12 22:03:38 -0800 |
| commit | 5506b7d7bbdb7622959d80a4a2fc18985a01d512 (patch) | |
| tree | 7e8643ffc2a2d0b79836d430f1c5e666538b5836 | |
| parent | f4f25b689b0da1c009028ed45ad1700c2cc8560a (diff) | |
selftests/bpf: make BPF_TARGET_ENDIAN non-recursive to speed up *.bpf.o build
BPF_TARGET_ENDIAN is used in CLANG_BPF_BUILD_RULE and co macros.
It is defined as a recursively expanded variable, meaning that it is
recomputed each time the value is needed. Thus, it is recomputed for
each *.bpf.o file compilation. The variable is computed by running a C
compiler in a shell. This significantly hinders parallel build
performance for *.bpf.o files.
This commit changes BPF_TARGET_ENDIAN to be a simply expanded
variable.
# Build performance stats before this commit
$ git clean -xfd; time make -j12
real 1m0.000s
...
# Build performance stats after this commit
$ git clean -xfd; time make -j12
real 0m43.605s
...
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20241213003224.837030-1-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/testing/selftests/bpf/Makefile | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index bb8cf8f5bf11..9e870e519c30 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -461,10 +461,10 @@ $(shell $(1) $(2) -dM -E - </dev/null | grep -E 'MIPS(EL|EB)|_MIPS_SZ(PTR|LONG) endef # Determine target endianness. -IS_LITTLE_ENDIAN = $(shell $(CC) -dM -E - </dev/null | \ +IS_LITTLE_ENDIAN := $(shell $(CC) -dM -E - </dev/null | \ grep 'define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__') -MENDIAN=$(if $(IS_LITTLE_ENDIAN),-mlittle-endian,-mbig-endian) -BPF_TARGET_ENDIAN=$(if $(IS_LITTLE_ENDIAN),--target=bpfel,--target=bpfeb) +MENDIAN:=$(if $(IS_LITTLE_ENDIAN),-mlittle-endian,-mbig-endian) +BPF_TARGET_ENDIAN:=$(if $(IS_LITTLE_ENDIAN),--target=bpfel,--target=bpfeb) ifneq ($(CROSS_COMPILE),) CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%)) |