tools/bpftool: Fix build slowdown

Commit ba2fd563b7 ("tools/bpftool: Support passing BPFTOOL_VERSION to
make") changed BPFTOOL_VERSION to a recursively expanded variable,
forcing it to be recomputed on every expansion of CFLAGS and
dramatically slowing down the bpftool build. Restore BPFTOOL_VERSION as
a simply expanded variable, guarded by an ifeq().

Fixes: ba2fd563b7 ("tools/bpftool: Support passing BPFTOOL_VERSION to make")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201110164310.2600671-8-jean-philippe@linaro.org
This commit is contained in:
Jean-Philippe Brucker 2020-11-10 17:43:11 +01:00 committed by Andrii Nakryiko
parent 2d9393fefb
commit 0639e5e97a

View File

@ -30,7 +30,9 @@ LIBBPF = $(LIBBPF_PATH)libbpf.a
LIBBPF_BOOTSTRAP_OUTPUT = $(BOOTSTRAP_OUTPUT)libbpf/
LIBBPF_BOOTSTRAP = $(LIBBPF_BOOTSTRAP_OUTPUT)libbpf.a
BPFTOOL_VERSION ?= $(shell make -rR --no-print-directory -sC ../../.. kernelversion)
ifeq ($(BPFTOOL_VERSION),)
BPFTOOL_VERSION := $(shell make -rR --no-print-directory -sC ../../.. kernelversion)
endif
$(LIBBPF_OUTPUT) $(BOOTSTRAP_OUTPUT) $(LIBBPF_BOOTSTRAP_OUTPUT):
$(QUIET_MKDIR)mkdir -p $@