[PATCH v1 2/5] perf build: Default BUILD_BPF_SKEL, warn/disable for missing deps
From: Ian Rogers
Date: Thu Sep 14 2023 - 17:20:05 EST
LIBBPF is dependent on zlib so move the NO_ZLIB and feature check
early to avoid statically building when zlib is disabled. This avoids
a linkage failure with perf and static libbpf when zlib isn't
specified.
Move BUILD_BPF_SKEL logic to one place and if not defined set
BUILD_BPF_SKEL to 1. Detect dependencies of building with BPF
skeletons and warn/disable if the dependencies aren't present.
Change Makefile.perf to contain BPF skeleton logic dependent on the
Makefile.config result and refresh the comment about BUILD_BPF_SKEL.
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/Makefile.config | 78 ++++++++++++++++++++++++--------------
tools/perf/Makefile.perf | 8 ++--
2 files changed, 53 insertions(+), 33 deletions(-)
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index d66b52407e19..f5ccbfc1a444 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -216,12 +216,6 @@ ifeq ($(call get-executable,$(BISON)),)
dummy := $(error Error: $(BISON) is missing on this system, please install it)
endif
-ifeq ($(BUILD_BPF_SKEL),1)
- ifeq ($(call get-executable,$(CLANG)),)
- dummy := $(error $(CLANG) is missing on this system, please install it to be able to build with BUILD_BPF_SKEL=1)
- endif
-endif
-
ifneq ($(OUTPUT),)
ifeq ($(shell expr $(shell $(BISON) --version | grep bison | sed -e 's/.\+ \([0-9]\+\).\([0-9]\+\).\([0-9]\+\)/\1\2\3/g') \>\= 371), 1)
BISON_FILE_PREFIX_MAP := --file-prefix-map=$(OUTPUT)=
@@ -530,6 +524,16 @@ ifdef CORESIGHT
endif
endif
+ifndef NO_ZLIB
+ ifeq ($(feature-zlib), 1)
+ CFLAGS += -DHAVE_ZLIB_SUPPORT
+ EXTLIBS += -lz
+ $(call detected,CONFIG_ZLIB)
+ else
+ NO_ZLIB := 1
+ endif
+endif
+
ifndef NO_LIBELF
CFLAGS += -DHAVE_LIBELF_SUPPORT
EXTLIBS += -lelf
@@ -571,22 +575,28 @@ ifndef NO_LIBELF
ifndef NO_LIBBPF
ifeq ($(feature-bpf), 1)
- CFLAGS += -DHAVE_LIBBPF_SUPPORT
- $(call detected,CONFIG_LIBBPF)
-
# detecting libbpf without LIBBPF_DYNAMIC, so make VF=1 shows libbpf detection status
$(call feature_check,libbpf)
ifdef LIBBPF_DYNAMIC
ifeq ($(feature-libbpf), 1)
EXTLIBS += -lbpf
+ CFLAGS += -DHAVE_LIBBPF_SUPPORT
+ $(call detected,CONFIG_LIBBPF)
$(call detected,CONFIG_LIBBPF_DYNAMIC)
else
dummy := $(error Error: No libbpf devel library found or older than v1.0, please install/update libbpf-devel);
endif
else
- # Libbpf will be built as a static library from tools/lib/bpf.
- LIBBPF_STATIC := 1
+ ifeq ($(NO_ZLIB), 1)
+ dummy := $(warning Warning: Statically building libbpf not possible as zlib is missing)
+ NO_LIBBPF := 1
+ else
+ # Libbpf will be built as a static library from tools/lib/bpf.
+ LIBBPF_STATIC := 1
+ $(call detected,CONFIG_LIBBPF)
+ CFLAGS += -DHAVE_LIBBPF_SUPPORT
+ endif
endif
endif
endif # NO_LIBBPF
@@ -663,16 +673,36 @@ ifndef NO_LIBBPF
endif
endif
-ifdef BUILD_BPF_SKEL
- $(call feature_check,clang-bpf-co-re)
- ifeq ($(feature-clang-bpf-co-re), 0)
- dummy := $(error Error: clang too old/not installed. Please install recent clang to build with BUILD_BPF_SKEL)
- endif
+ifndef BUILD_BPF_SKEL
+ # BPF skeletons control a large number of perf features, by default
+ # they are enabled.
+ BUILD_BPF_SKEL := 1
+endif
+
+ifeq ($(BUILD_BPF_SKEL),1)
ifeq ($(filter -DHAVE_LIBBPF_SUPPORT, $(CFLAGS)),)
- dummy := $(error Error: BPF skeleton support requires libbpf)
+ dummy := $(warning Warning: Disabled BPF skeletons as libbpf is required)
+ BUILD_BPF_SKEL := 0
+ else ifeq ($(filter -DHAVE_LIBELF_SUPPORT, $(CFLAGS)),)
+ dummy := $(warning Warning: Disabled BPF skeletons as libelf is required by bpftool)
+ BUILD_BPF_SKEL := 0
+ else ifeq ($(filter -DHAVE_ZLIB_SUPPORT, $(CFLAGS)),)
+ dummy := $(warning Warning: Disabled BPF skeletons as zlib is required by bpftool)
+ BUILD_BPF_SKEL := 0
+ else ifeq ($(call get-executable,$(CLANG)),)
+ dummy := $(warning Warning: Disabled BPF skeletons as clang ($(CLANG)) is missing)
+ BUILD_BPF_SKEL := 0
+ else
+ $(call feature_check,clang-bpf-co-re)
+ ifeq ($(feature-clang-bpf-co-re), 0)
+ dummy := $(warning Warning: Disabled BPF skeletons as clang is too old)
+ BUILD_BPF_SKEL := 0
+ endif
+ endif
+ ifeq ($(BUILD_BPF_SKEL),1)
+ $(call detected,CONFIG_PERF_BPF_SKEL)
+ CFLAGS += -DHAVE_BPF_SKEL
endif
- $(call detected,CONFIG_PERF_BPF_SKEL)
- CFLAGS += -DHAVE_BPF_SKEL
endif
ifndef GEN_VMLINUX_H
@@ -946,16 +976,6 @@ ifndef NO_DEMANGLE
endif
endif
-ifndef NO_ZLIB
- ifeq ($(feature-zlib), 1)
- CFLAGS += -DHAVE_ZLIB_SUPPORT
- EXTLIBS += -lz
- $(call detected,CONFIG_ZLIB)
- else
- NO_ZLIB := 1
- endif
-endif
-
ifndef NO_LZMA
ifeq ($(feature-lzma), 1)
CFLAGS += -DHAVE_LZMA_SUPPORT
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 8d0f6d2bbc7a..98604e396ac3 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -120,7 +120,7 @@ include ../scripts/utilities.mak
#
# Define NO_LIBDEBUGINFOD if you do not want support debuginfod
#
-# Define BUILD_BPF_SKEL to enable BPF skeletons
+# Set BUILD_BPF_SKEL to 0 to override BUILD_BPF_SKEL and not build BPF skeletons
#
# Define BUILD_NONDISTRO to enable building an linking against libbfd and
# libiberty distribution license incompatible libraries.
@@ -1042,7 +1042,7 @@ SKELETONS += $(SKEL_OUT)/augmented_raw_syscalls.skel.h
$(SKEL_TMP_OUT) $(LIBAPI_OUTPUT) $(LIBBPF_OUTPUT) $(LIBPERF_OUTPUT) $(LIBSUBCMD_OUTPUT) $(LIBSYMBOL_OUTPUT):
$(Q)$(MKDIR) -p $@
-ifdef BUILD_BPF_SKEL
+ifeq ($(CONFIG_PERF_BPF_SKEL),y)
BPFTOOL := $(SKEL_TMP_OUT)/bootstrap/bpftool
# Get Clang's default includes on this system, as opposed to those seen by
# '--target=bpf'. This fixes "missing" files on some architectures/distros,
@@ -1120,11 +1120,11 @@ bpf-skel: $(SKELETONS)
.PRECIOUS: $(SKEL_TMP_OUT)/%.bpf.o
-else # BUILD_BPF_SKEL
+else # CONFIG_PERF_BPF_SKEL
bpf-skel:
-endif # BUILD_BPF_SKEL
+endif # CONFIG_PERF_BPF_SKEL
bpf-skel-clean:
$(call QUIET_CLEAN, bpf-skel) $(RM) -r $(SKEL_TMP_OUT) $(SKELETONS)
--
2.42.0.459.ge4e396fd5e-goog