From 8f12a2ff00e5e48ad5618167bac72cad7c9f214e Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 4 May 2018 11:56:15 -0300 Subject: perf bpf: Add 'examples' directories The first one is the bare minimum that bpf infrastructure accepts before it expects actual events to be set up: $ cat tools/perf/examples/bpf/empty.c char _license[] __attribute__((section("license"), used)) = "GPL"; int _version __attribute__((section("version"), used)) = LINUX_VERSION_CODE; $ If you remove that "version" line, then it will be refused with: # perf trace -e tools/perf/examples/bpf/empty.c event syntax error: 'tools/perf/examples/bpf/empty.c' \___ Failed to load tools/perf/examples/bpf/empty.c from source: 'version' section incorrect or lost (add -v to see detail) Run 'perf list' for a list of valid events Usage: perf trace [] [] or: perf trace [] -- [] or: perf trace record [] [] or: perf trace record [] -- [] -e, --event event/syscall selector. use 'perf list' to list available events # The next ones will, step by step, show simple filters, then the needs for headers will be made clear, it will be put in place and tested with new examples, rinse, repeat. Back to using this first one to test the perf+bpf infrastructure: If we run it will fail, as no functions are present connecting with, say, a tracepoint or a function using the kprobes or uprobes infrastructure: # perf trace -e tools/perf/examples/bpf/empty.c WARNING: event parser found nothing invalid or unsupported event: 'tools/perf/examples/bpf/empty.c' Run 'perf list' for a list of valid events Usage: perf trace [] [] or: perf trace [] -- [] or: perf trace record [] [] or: perf trace record [] -- [] -e, --event event/syscall selector. use 'perf list' to list available events # But, if we set things up to dump the generated object file to a file, and do this after having run 'make install', still on the developer's $HOME directory: # cat ~/.perfconfig [llvm] dump-obj = true # # perf trace -e ~acme/lib/examples/perf/bpf/empty.c LLVM: dumping /home/acme/lib/examples/perf/bpf/empty.o WARNING: event parser found nothing invalid or unsupported event: '/home/acme/lib/examples/perf/bpf/empty.c' # We can look at the dumped object file: # ls -la ~acme/lib/examples/perf/bpf/empty.o -rw-r--r--. 1 root root 576 May 4 12:10 /home/acme/lib/examples/perf/bpf/empty.o # file ~acme/lib/examples/perf/bpf/empty.o /home/acme/lib/examples/perf/bpf/empty.o: ELF 64-bit LSB relocatable, *unknown arch 0xf7* version 1 (SYSV), not stripped # readelf -sw ~acme/lib/examples/perf/bpf/empty.o Symbol table '.symtab' contains 3 entries: Num: Value Size Type Bind Vis Ndx Name 0: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND 1: 0000000000000000 0 NOTYPE GLOBAL DEFAULT 3 _license 2: 0000000000000000 0 NOTYPE GLOBAL DEFAULT 4 _version # # tools/bpf/bpftool/bpftool --pretty ~acme/lib/examples/perf/bpf/empty.o null # Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-y7dkhakejz3013o0w21n98xd@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Makefile.config | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'tools/perf/Makefile.config') diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config index 3bca9a733f0e..b5ac356ba323 100644 --- a/tools/perf/Makefile.config +++ b/tools/perf/Makefile.config @@ -886,6 +886,7 @@ endif # Among the variables below, these: # perfexecdir # perf_include_dir +# perf_examples_dir # template_dir # mandir # infodir @@ -906,6 +907,7 @@ mandir = share/man infodir = share/info perfexecdir = libexec/perf-core perf_include_dir = lib/include/perf +perf_examples_dir = lib/examples/perf sharedir = $(prefix)/share template_dir = share/perf-core/templates STRACE_GROUPS_DIR = share/perf-core/strace/groups @@ -937,6 +939,7 @@ mandir_SQ = $(subst ','\'',$(mandir)) infodir_SQ = $(subst ','\'',$(infodir)) perfexecdir_SQ = $(subst ','\'',$(perfexecdir)) perf_include_dir_SQ = $(subst ','\'',$(perf_include_dir)) +perf_examples_dir_SQ = $(subst ','\'',$(perf_examples_dir)) template_dir_SQ = $(subst ','\'',$(template_dir)) htmldir_SQ = $(subst ','\'',$(htmldir)) tipdir_SQ = $(subst ','\'',$(tipdir)) @@ -948,16 +951,19 @@ srcdir_SQ = $(subst ','\'',$(srcdir)) ifneq ($(filter /%,$(firstword $(perfexecdir))),) perfexec_instdir = $(perfexecdir) perf_include_instdir = $(perf_include_dir) +perf_examples_instdir = $(perf_examples_dir) STRACE_GROUPS_INSTDIR = $(STRACE_GROUPS_DIR) tip_instdir = $(tipdir) else perfexec_instdir = $(prefix)/$(perfexecdir) perf_include_instdir = $(prefix)/$(perf_include_dir) +perf_examples_instdir = $(prefix)/$(perf_examples_dir) STRACE_GROUPS_INSTDIR = $(prefix)/$(STRACE_GROUPS_DIR) tip_instdir = $(prefix)/$(tipdir) endif perfexec_instdir_SQ = $(subst ','\'',$(perfexec_instdir)) perf_include_instdir_SQ = $(subst ','\'',$(perf_include_instdir)) +perf_examples_instdir_SQ = $(subst ','\'',$(perf_examples_instdir)) STRACE_GROUPS_INSTDIR_SQ = $(subst ','\'',$(STRACE_GROUPS_INSTDIR)) tip_instdir_SQ = $(subst ','\'',$(tip_instdir)) @@ -1006,6 +1012,7 @@ $(call detected_var,STRACE_GROUPS_DIR_SQ) $(call detected_var,prefix_SQ) $(call detected_var,perfexecdir_SQ) $(call detected_var,perf_include_dir_SQ) +$(call detected_var,perf_examples_dir_SQ) $(call detected_var,tipdir_SQ) $(call detected_var,srcdir_SQ) $(call detected_var,LIBDIR) -- cgit v1.2.3