From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Clark Williams <williams@redhat.com>,
linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Adrian Hunter <adrian.hunter@intel.com>,
David Ahern <dsahern@gmail.com>, Jiri Olsa <jolsa@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Wang Nan <wangnan0@huawei.com>
Subject: [PATCH 04/11] perf bpf: Add 'examples' directories
Date: Wed, 16 May 2018 11:49:01 -0300 [thread overview]
Message-ID: <20180516144908.22212-5-acme@kernel.org> (raw)
In-Reply-To: <20180516144908.22212-1-acme@kernel.org>
From: Arnaldo Carvalho de Melo <acme@redhat.com>
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 [<options>] [<command>]
or: perf trace [<options>] -- <command> [<options>]
or: perf trace record [<options>] [<command>]
or: perf trace record [<options>] -- <command> [<options>]
-e, --event <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 [<options>] [<command>]
or: perf trace [<options>] -- <command> [<options>]
or: perf trace record [<options>] [<command>]
or: perf trace record [<options>] -- <command> [<options>]
-e, --event <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'
<SNIP>
#
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 <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-y7dkhakejz3013o0w21n98xd@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/Makefile.config | 7 +++++++
tools/perf/Makefile.perf | 3 +++
tools/perf/examples/bpf/empty.c | 2 ++
3 files changed, 12 insertions(+)
create mode 100644 tools/perf/examples/bpf/empty.c
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)
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index d9663b1cf43e..9343b7d945bb 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -770,6 +770,9 @@ endif
ifndef NO_LIBBPF
$(call QUIET_INSTALL, lib) \
$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perf_include_instdir_SQ)/bpf'
+ $(call QUIET_INSTALL, lib) \
+ $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(perf_examples_instdir_SQ)/bpf'
+ $(INSTALL) examples/bpf/*.c '$(DESTDIR_SQ)$(perf_examples_instdir_SQ)/bpf'
endif
$(call QUIET_INSTALL, perf-archive) \
$(INSTALL) $(OUTPUT)perf-archive -t '$(DESTDIR_SQ)$(perfexec_instdir_SQ)'
diff --git a/tools/perf/examples/bpf/empty.c b/tools/perf/examples/bpf/empty.c
new file mode 100644
index 000000000000..78754df53ac1
--- /dev/null
+++ b/tools/perf/examples/bpf/empty.c
@@ -0,0 +1,2 @@
+char _license[] __attribute__((section("license"), used)) = "GPL";
+int _version __attribute__((section("version"), used)) = LINUX_VERSION_CODE;
--
2.14.3
next prev parent reply other threads:[~2018-05-16 14:49 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-16 14:48 [GIT PULL 00/11] perf/core improvements and fixes Arnaldo Carvalho de Melo
2018-05-16 14:48 ` [PATCH 01/11] perf tests parse-events: Add intel_pt parse test Arnaldo Carvalho de Melo
2018-05-16 21:33 ` Kim Phillips
2018-05-17 20:15 ` Arnaldo Carvalho de Melo
2018-05-17 20:58 ` Jiri Olsa
2018-05-17 22:54 ` Kim Phillips
2018-05-18 14:13 ` Arnaldo Carvalho de Melo
2018-05-16 14:48 ` [PATCH 02/11] perf buildid-cache: Warn --purge-all failures Arnaldo Carvalho de Melo
2018-05-16 14:49 ` [PATCH 03/11] perf llvm-utils: Add bpf include path to clang command line Arnaldo Carvalho de Melo
2018-05-16 14:49 ` Arnaldo Carvalho de Melo [this message]
2018-05-16 14:49 ` [PATCH 05/11] perf bpf: Add bpf.h to be used in eBPF proggies Arnaldo Carvalho de Melo
2018-05-16 14:49 ` [PATCH 06/11] perf bpf: Add kprobe example to catch 5s naps Arnaldo Carvalho de Melo
2018-05-16 14:49 ` [PATCH 07/11] perf bpf: Add license(NAME) helper Arnaldo Carvalho de Melo
2018-05-16 14:49 ` [PATCH 08/11] perf bpf: Add probe() helper to reduce kprobes boilerplate Arnaldo Carvalho de Melo
2018-05-16 14:49 ` [PATCH 09/11] perf tools: Use the "_stest" symbol to identify the kernel map when loading kcore Arnaldo Carvalho de Melo
2018-05-16 14:49 ` [PATCH 10/11] perf parse-events: Handle uncore event aliases in small groups properly Arnaldo Carvalho de Melo
2018-05-16 14:49 ` [PATCH 11/11] perf bpf: Fix NULL return handling in bpf__prepare_load() Arnaldo Carvalho de Melo
2018-05-16 15:58 ` [GIT PULL 00/11] perf/core improvements and fixes Ingo Molnar
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