Andrii Nakryiko andrii.nakryiko@gmail.com writes:
On Fri, Jan 17, 2020 at 5:37 AM Toke Høiland-Jørgensen toke@redhat.com wrote:
From: Toke Høiland-Jørgensen toke@redhat.com
The runqslower tool refuses to build without a file to read vmlinux BTF from. The build fails with an error message to override the location by setting the VMLINUX_BTF variable if autodetection fails. However, the Makefile doesn't actually work with that override - the error message is still emitted.
Fix this by including the value of VMLINUX_BTF in the expansion, and only emitting the error message if the *result* is empty. Also permit running 'make clean' even though no VMLINUX_BTF is set.
Fixes: 9c01546d26d2 ("tools/bpf: Add runqslower tool to tools/bpf") Signed-off-by: Toke Høiland-Jørgensen toke@redhat.com
approach looks good, thanks, few nits below
tools/bpf/runqslower/Makefile | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/tools/bpf/runqslower/Makefile b/tools/bpf/runqslower/Makefile index cff2fbcd29a8..b62fc9646c39 100644 --- a/tools/bpf/runqslower/Makefile +++ b/tools/bpf/runqslower/Makefile @@ -10,13 +10,9 @@ CFLAGS := -g -Wall
# Try to detect best kernel BTF source KERNEL_REL := $(shell uname -r) -ifneq ("$(wildcard /sys/kernel/btf/vmlinux)","") -VMLINUX_BTF := /sys/kernel/btf/vmlinux -else ifneq ("$(wildcard /boot/vmlinux-$(KERNEL_REL))","") -VMLINUX_BTF := /boot/vmlinux-$(KERNEL_REL) -else -$(error "Can't detect kernel BTF, use VMLINUX_BTF to specify it explicitly") -endif +VMLINUX_BTF_PATHS := /sys/kernel/btf/vmlinux /boot/vmlinux-$(KERNEL_REL) +VMLINUX_BTF_PATH := $(abspath $(or $(VMLINUX_BTF),$(firstword \
$(wildcard $(VMLINUX_BTF_PATHS)))))you can drop abspath, relative path for VMLINUX_BTF would work just fine
OK.
abs_out := $(abspath $(OUTPUT)) ifeq ($(V),1) @@ -67,9 +63,13 @@ $(OUTPUT): $(call msg,MKDIR,$@) $(Q)mkdir -p $(OUTPUT)
-$(OUTPUT)/vmlinux.h: $(VMLINUX_BTF) | $(OUTPUT) $(BPFTOOL) +$(OUTPUT)/vmlinux.h: $(VMLINUX_BTF_PATH) | $(OUTPUT) $(BPFTOOL) $(call msg,GEN,$@)
$(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
@if [ ! -e "$(VMLINUX_BTF_PATH)" ] ; then \$(Q), not @
This was actually deliberate, since I was replacing an $(error) (which doesn't show up in V=1 output). But OK, I guess we can output the whole if statement as well on verbose builds...
echo "Couldn't find kernel BTF; set VMLINUX_BTF to specify its location."; \exit 1;\nit: please align 's (same above for VMLONUX_BTF_PATH) at the right edge as it's done everywhere in this Makefile
Right, I'll try to fix those up (for the whole series). My emacs is being a bit weird with displaying tabstops, so some of these look aligned when I'm editing. I'll see if I can figure out how to fix this so it becomes obvious while I'm making changes...
-Toke