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Wang Nan 7630b3e28d perf tools: Enable passing event to BPF object 
A new syntax is added to the parser so that the user can access
predefined perf events in BPF objects.

After this patch, BPF programs for perf are finally able to utilize
bpf_perf_event_read() introduced in commit 35578d7984 ("bpf: Implement
function bpf_perf_event_read() that get the selected hardware PMU
counter").

Test result:

  # cat test_bpf_map_2.c
  /************************ BEGIN **************************/
  #include <uapi/linux/bpf.h>
  #define SEC(NAME) __attribute__((section(NAME), used))
  struct bpf_map_def {
      unsigned int type;
      unsigned int key_size;
      unsigned int value_size;
      unsigned int max_entries;
  };
  static int (*trace_printk)(const char *fmt, int fmt_size, ...) =
      (void *)BPF_FUNC_trace_printk;
  static int (*get_smp_processor_id)(void) =
      (void *)BPF_FUNC_get_smp_processor_id;
  static int (*perf_event_read)(struct bpf_map_def *, int) =
      (void *)BPF_FUNC_perf_event_read;

  struct bpf_map_def SEC("maps") pmu_map = {
      .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
      .key_size = sizeof(int),
      .value_size = sizeof(int),
      .max_entries = __NR_CPUS__,
  };
  SEC("func_write=sys_write")
  int func_write(void *ctx)
  {
      unsigned long long val;
      char fmt[] = "sys_write:        pmu=%llu\n";
      val = perf_event_read(&pmu_map, get_smp_processor_id());
      trace_printk(fmt, sizeof(fmt), val);
      return 0;
  }

  SEC("func_write_return=sys_write%return")
  int func_write_return(void *ctx)
  {
      unsigned long long val = 0;
      char fmt[] = "sys_write_return: pmu=%llu\n";
      val = perf_event_read(&pmu_map, get_smp_processor_id());
      trace_printk(fmt, sizeof(fmt), val);
      return 0;
  }
  char _license[] SEC("license") = "GPL";
  int _version SEC("version") = LINUX_VERSION_CODE;
  /************************* END ***************************/

Normal case:

  # echo "" > /sys/kernel/debug/tracing/trace
  # perf record -i -e cycles -e './test_bpf_map_2.c/map:pmu_map.event=cycles/' ls /
  [SNIP]
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.013 MB perf.data (7 samples) ]
  # cat /sys/kernel/debug/tracing/trace | grep ls
                ls-17066 [000] d... 938449.863301: : sys_write:        pmu=1157327
                ls-17066 [000] dN.. 938449.863342: : sys_write_return: pmu=1225218
                ls-17066 [000] d... 938449.863349: : sys_write:        pmu=1241922
                ls-17066 [000] dN.. 938449.863369: : sys_write_return: pmu=1267445

Normal case (system wide):

  # echo "" > /sys/kernel/debug/tracing/trace
  # perf record -i -e cycles -e './test_bpf_map_2.c/map:pmu_map.event=cycles/' -a
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.811 MB perf.data (120 samples) ]

  # cat /sys/kernel/debug/tracing/trace | grep -v '18446744073709551594' | grep -v perf | head -n 20
  [SNIP]
  #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
  #              | |       |   ||||       |         |
             gmain-30828 [002] d... 2740551.068992: : sys_write:        pmu=84373
             gmain-30828 [002] d... 2740551.068992: : sys_write_return: pmu=87696
             gmain-30828 [002] d... 2740551.068996: : sys_write:        pmu=100658
             gmain-30828 [002] d... 2740551.068997: : sys_write_return: pmu=102572

Error case 1:

  # perf record -e './test_bpf_map_2.c' ls /
  [SNIP]
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.014 MB perf.data ]
  # cat /sys/kernel/debug/tracing/trace | grep ls
                ls-17115 [007] d... 2724279.665625: : sys_write:        pmu=18446744073709551614
                ls-17115 [007] dN.. 2724279.665651: : sys_write_return: pmu=18446744073709551614
                ls-17115 [007] d... 2724279.665658: : sys_write:        pmu=18446744073709551614
                ls-17115 [007] dN.. 2724279.665677: : sys_write_return: pmu=18446744073709551614

  (18446744073709551614 is 0xfffffffffffffffe (-2))

Error case 2:

  # perf record -e cycles -e './test_bpf_map_2.c/map:pmu_map.event=evt/' -a
  event syntax error: '..ps:pmu_map.event=evt/'
                                    \___ Event not found for map setting

  Hint:	Valid config terms:
       	map:[<arraymap>].value=[value]
       	map:[<eventmap>].event=[event]
  [SNIP]

Error case 3:
  # ls /proc/2348/task/
  2348  2505  2506  2507  2508
  # perf record -i -e cycles -e './test_bpf_map_2.c/map:pmu_map.event=cycles/' -p 2348
  ERROR: Apply config to BPF failed: Cannot set event to BPF map in multi-thread tracing

Error case 4:
  # perf record -e cycles -e './test_bpf_map_2.c/map:pmu_map.event=cycles/' ls /
  ERROR: Apply config to BPF failed: Doesn't support inherit event (Hint: use -i to turn off inherit)

Error case 5:
  # perf record -i -e raw_syscalls:sys_enter -e './test_bpf_map_2.c/map:pmu_map.event=raw_syscalls:sys_enter/' ls
  ERROR: Apply config to BPF failed: Can only put raw, hardware and BPF output event into a BPF map

Error case 6:
  # perf record -i -e './test_bpf_map_2.c/map:pmu_map.event=123/' ls /
  event syntax error: '.._map.event=123/'
                                    \___ Incorrect value type for map
  [SNIP]

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Cody P Schafer <dev@codyps.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jeremie.galarneau@efficios.com>
Cc: Kirill Smelkov <kirr@nexedi.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1456132275-98875-7-git-send-email-wangnan0@huawei.com
Signed-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
 		2016-02-22 12:30:50 -03:00
..
Documentation perf record: Add --all-user/--all-kernel options 2016-02-18 10:48:44 -03:00
arch perf tools: Rename parse_events__free_terms() to parse_events_terms__delete() 2016-02-12 17:09:17 -03:00
bench perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
config perf build: Add libcrypto feature detection 2016-02-05 09:46:45 -03:00
jvmti perf jvmti: Add check for java alternatives cmd in Makefile 2016-02-16 17:12:46 -03:00
python perf python: Support the PERF_RECORD_SWITCH event 2015-10-07 19:41:50 -03:00
scripts perf python scripting: Append examples to err msg about audit-libs-python 2016-02-12 11:30:27 -03:00
tests perf tools: Enable config and setting names for legacy cache events 2016-02-19 19:12:51 -03:00
trace/strace/groups perf trace: Add read/write to the file group 2015-09-04 13:22:06 -03:00
ui perf tools: Fix assertion failure on dynamic entry 2016-02-22 12:07:14 -03:00
util perf tools: Enable passing event to BPF object 2016-02-22 12:30:50 -03:00
.gitignore perf tools: Add Intel PT instruction decoder 2015-08-17 11:11:36 -03:00
Build perf tools: Set and pass DOCDIR to builtin-report.c 2016-01-12 12:42:07 -03:00
CREDITS
…
MANIFEST perf tools: Add missing sources to perf's MANIFEST 2016-01-11 12:09:25 -03:00
Makefile perf build tests: Do parallell builds with 'build-test' 2016-02-04 15:57:00 -03:00
Makefile.perf perf build: Add EXTRA_LDFLAGS option to makefile 2016-02-12 11:30:20 -03:00
builtin-annotate.c perf hists: Introduce perf_evsel__output_resort function 2016-02-03 11:13:11 -03:00
builtin-bench.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-buildid-cache.c perf tools: Move timestamp creation to util 2016-01-29 17:30:06 -03:00
builtin-buildid-list.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-config.c perf config: Add '--system' and '--user' options to select which config file is used 2016-02-12 10:54:46 -03:00
builtin-data.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-diff.c perf diff: Use perf_hpp__register_sort_field interface 2016-01-08 12:59:30 -03:00
builtin-evlist.c perf evlist: Add --trace-fields option to show trace fields 2016-01-08 14:23:02 -03:00
builtin-help.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-inject.c perf inject: Add jitdump mmap injection support 2016-02-05 09:46:45 -03:00
builtin-kmem.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-kvm.c perf kvm/powerpc: Port perf kvm stat to powerpc 2016-01-29 17:49:54 -03:00
builtin-list.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-lock.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-mem.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-probe.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-record.c perf record: Apply config to BPF objects before recording 2016-02-22 12:28:02 -03:00
builtin-report.c perf report: Check error during report__collapse_hists() 2016-02-19 19:17:50 -03:00
builtin-sched.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-script.c perf script: Align event name properly 2016-01-08 12:57:26 -03:00
builtin-stat.c perf stat: Bail out on unsupported event config modifiers 2016-02-19 19:12:49 -03:00
builtin-timechart.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-top.c perf top: Move UI initialization ahead of sort setup 2016-02-03 12:24:03 -03:00
builtin-trace.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
builtin-version.c perf tools: Move cmd_version() to builtin-version.c 2015-12-09 13:42:03 -03:00
builtin.h perf tools: Add 'perf config' command 2015-11-23 18:31:24 -03:00
command-list.txt perf tools: Do not show trace command if it's not compiled in 2016-01-08 12:46:17 -03:00
design.txt perf tools: Update some code references in design.txt 2014-03-18 18:17:06 -03:00
perf-archive.sh
…
perf-completion.sh perf tools: Avoid confusion with preloaded bash function for perf bash completion 2015-03-19 13:53:27 -03:00
perf-read-vdso.c perf tools: Build programs to copy 32-bit compatibility 2014-10-29 10:32:48 -02:00
perf-sys.h perf tools: Move generic barriers out of perf-sys.h 2015-05-08 16:05:08 -03:00
perf-with-kcore.sh perf tools: Fix perf-with-kcore handling of arguments containing spaces 2015-08-06 16:48:27 -03:00
perf.c perf tools: Initialize libapi debug output 2016-02-16 17:12:59 -03:00
perf.h perf record: Add --all-user/--all-kernel options 2016-02-18 10:48:44 -03:00