The runqslower build invokes a nested make, but the selected LLVM toolchain (via LLVM=-<version>) is not propagated. This causes the sub-make to call the system-default 'clang' and 'llvm-strip' even when a specific LLVM version is intended.
# LLVM=-20 V=1 make -C tools/testing/selftests/bpf ... make -C tools/bpf/runqslower ... clang -g -O2 --target=bpfel -I... -c runqslower.bpf.c -o runqslower.bpf.o && \ llvm-strip -g runqslower.bpf.o /bin/sh: 1: clang: not found
(expected: clang-20 and llvm-strip-20)
Propagate CLANG and LLVM_STRIP to the sub-make to ensure LLVM version consistency across all builds.
Signed-off-by: Hoyeon Lee hoyeon.lee@suse.com --- tools/testing/selftests/bpf/Makefile | 1 + tools/testing/selftests/lib.mk | 1 + 2 files changed, 2 insertions(+)
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 34ea23c63bd5..79ab69920dca 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -306,6 +306,7 @@ endif
$(OUTPUT)/runqslower: $(BPFOBJ) | $(DEFAULT_BPFTOOL) $(RUNQSLOWER_OUTPUT) $(Q)$(MAKE) $(submake_extras) -C $(TOOLSDIR)/bpf/runqslower \ + CLANG=$(CLANG) LLVM_STRIP=$(LLVM_STRIP) \ OUTPUT=$(RUNQSLOWER_OUTPUT) VMLINUX_BTF=$(VMLINUX_BTF) \ BPFTOOL_OUTPUT=$(HOST_BUILD_DIR)/bpftool/ \ BPFOBJ_OUTPUT=$(BUILD_DIR)/libbpf/ \ diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk index a448fae57831..f14255b2afbd 100644 --- a/tools/testing/selftests/lib.mk +++ b/tools/testing/selftests/lib.mk @@ -8,6 +8,7 @@ LLVM_SUFFIX := $(LLVM) endif
CLANG := $(LLVM_PREFIX)clang$(LLVM_SUFFIX) +LLVM_STRIP := $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
CLANG_TARGET_FLAGS_arm := arm-linux-gnueabi CLANG_TARGET_FLAGS_arm64 := aarch64-linux-gnu
On Tue, Nov 18, 2025 at 8:38 PM Hoyeon Lee hoyeon.lee@suse.com wrote:
The runqslower build invokes a nested make, but the selected LLVM
I think runqslower in kernel repo has long since served its purpose. There is no point in maintaining its Makefile. The tool itself lives in BCC repo. Its original purpose was to show real-world BPF-based tooling end-to-end setup and implementation. BPF, libbpf, entire BPF ecosystem has evolved and grown, I think we can remove runqslower now. Do you mind just sending a patch dropping it instead?
pw-bot: cr
toolchain (via LLVM=-<version>) is not propagated. This causes the sub-make to call the system-default 'clang' and 'llvm-strip' even when a specific LLVM version is intended.
# LLVM=-20 V=1 make -C tools/testing/selftests/bpf ... make -C tools/bpf/runqslower ... clang -g -O2 --target=bpfel -I... -c runqslower.bpf.c -o runqslower.bpf.o && \ llvm-strip -g runqslower.bpf.o /bin/sh: 1: clang: not found (expected: clang-20 and llvm-strip-20)Propagate CLANG and LLVM_STRIP to the sub-make to ensure LLVM version consistency across all builds.
Signed-off-by: Hoyeon Lee hoyeon.lee@suse.com
tools/testing/selftests/bpf/Makefile | 1 + tools/testing/selftests/lib.mk | 1 + 2 files changed, 2 insertions(+)
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 34ea23c63bd5..79ab69920dca 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -306,6 +306,7 @@ endif
$(OUTPUT)/runqslower: $(BPFOBJ) | $(DEFAULT_BPFTOOL) $(RUNQSLOWER_OUTPUT) $(Q)$(MAKE) $(submake_extras) -C $(TOOLSDIR)/bpf/runqslower \
CLANG=$(CLANG) LLVM_STRIP=$(LLVM_STRIP) \ OUTPUT=$(RUNQSLOWER_OUTPUT) VMLINUX_BTF=$(VMLINUX_BTF) \ BPFTOOL_OUTPUT=$(HOST_BUILD_DIR)/bpftool/ \ BPFOBJ_OUTPUT=$(BUILD_DIR)/libbpf/ \diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk index a448fae57831..f14255b2afbd 100644 --- a/tools/testing/selftests/lib.mk +++ b/tools/testing/selftests/lib.mk @@ -8,6 +8,7 @@ LLVM_SUFFIX := $(LLVM) endif
CLANG := $(LLVM_PREFIX)clang$(LLVM_SUFFIX) +LLVM_STRIP := $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
CLANG_TARGET_FLAGS_arm := arm-linux-gnueabi CLANG_TARGET_FLAGS_arm64 := aarch64-linux-gnu -- 2.51.1
linux-kselftest-mirror@lists.linaro.org
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Andrii Nakryiko -
Hoyeon Lee