1. 02 Aug, 2016 1 commit
  2. 15 Jul, 2016 6 commits
    • Wang Nan's avatar
      perf record: Add --tail-synthesize option · 4ea648ae
      Wang Nan authored
      When working with overwritable ring buffer there's a inconvenience
      problem: if perf dumps data after a long period after it starts,
      non-sample events may lost, which makes following 'perf report' unable
      to identify proc name and mmap layout. For example:
      
       # perf record -m 4 -e raw_syscalls:* -g --overwrite --switch-output \
              dd if=/dev/zero of=/dev/null
      
      send SIGUSR2 after dd runs long enough. The resuling perf.data lost
      correct comm and mmap events:
      
       # perf script -i perf.data.2016061522374354
       perf 24478 [004] 2581325.601789:  raw_syscalls:sys_exit: NR 0 = 512
       ^^^^
       Should be 'dd'
                         27b2e8 syscall_slow_exit_work+0xfe2000e3 (/lib/modules/4.6.0-rc3+/build/vmlinux)
                         203cc7 do_syscall_64+0xfe200117 (/lib/modules/4.6.0-rc3+/build/vmlinux)
                         b18d83 return_from_SYSCALL_64+0xfe200000 (/lib/modules/4.6.0-rc3+/build/vmlinux)
                   7f47c417edf0 [unknown] ([unknown])
                   ^^^^^^^^^^^^
                   Fail to unwind
      
      This patch provides a '--tail-synthesize' option, allows perf to collect
      system status when finalizing output file. In resuling output file, the
      non-sample events reflect system status when dumping data.
      
      After this patch:
       # perf record -m 4 -e raw_syscalls:* -g --overwrite --switch-output --tail-synthesize \
              dd if=/dev/zero of=/dev/null
      
       # perf script -i perf.data.2016061600544998
       dd 27364 [004] 2583244.994464: raw_syscalls:sys_enter: NR 1 (1, ...
       ^^
       Correct comm
                         203a18 syscall_trace_enter_phase2+0xfe2001a8 ([kernel.kallsyms])
                         203aa5 syscall_trace_enter+0xfe200055 ([kernel.kallsyms])
                         203caa do_syscall_64+0xfe2000fa ([kernel.kallsyms])
                         b18d83 return_from_SYSCALL_64+0xfe200000 ([kernel.kallsyms])
                          d8e50 __GI___libc_write+0xffff01d9639f4010 (/tmp/oxygen_root-w00229757/lib64/libc-2.18.so)
                          ^^^^^
                          Correct unwind
      
      This option doesn't aim to solve this problem completely. If a process
      terminates before SIGUSR2, we still lost its COMM and MMAP events. For
      example, we can't unwind correctly from the final perf.data we get from
      the previous example, because when perf collects the final output file
      (when we press C-c), 'dd' has been terminated so its '/proc/<pid>/mmap'
      becomes empty.
      
      However, this is a cheaper choice. To completely solve this problem we
      need to continously output non-sample events. To satisify the
      requirement of daemonization, we need to merge them periodically. It is
      possible but requires much more code and cycles.
      
      Automatically select --tail-synthesize when --overwrite is provided.
      Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
      Cc: He Kuang <hekuang@huawei.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Nilay Vaish <nilayvaish@gmail.com>
      Cc: Zefan Li <lizefan@huawei.com>
      Cc: pi3orama@163.com
      Link: http://lkml.kernel.org/r/1468485287-33422-16-git-send-email-wangnan0@huawei.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      4ea648ae
    • Wang Nan's avatar
      perf tools: Enable overwrite settings · 626a6b78
      Wang Nan authored
      This patch allows following config terms and option:
      
      Globally setting events to overwrite;
      
        # perf record --overwrite ...
      
      Set specific events to be overwrite or no-overwrite.
      
        # perf record --event cycles/overwrite/ ...
        # perf record --event cycles/no-overwrite/ ...
      
      Add missing config terms and update the config term array size because
      the longest string length has changed.
      
      For overwritable events, it automatically selects attr.write_backward
      since perf requires it to be backward for reading.
      
      Test result:
      
        # perf record --overwrite -e syscalls:*enter_nanosleep* usleep 1
        [ perf record: Woken up 2 times to write data ]
        [ perf record: Captured and wrote 0.011 MB perf.data (1 samples) ]
        # perf evlist -v
        syscalls:sys_enter_nanosleep: type: 2, size: 112, config: 0x134, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|PERIOD|RAW, disabled: 1, inherit: 1, mmap: 1, comm: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, write_backward: 1
        # Tip: use 'perf evlist --trace-fields' to show fields for tracepoint events
      Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
      Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Nilay Vaish <nilayvaish@gmail.com>
      Cc: Zefan Li <lizefan@huawei.com>
      Cc: pi3orama@163.com
      Link: http://lkml.kernel.org/r/1468485287-33422-14-git-send-email-wangnan0@huawei.comSigned-off-by: default avatarHe Kuang <hekuang@huawei.com>
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      626a6b78
    • Wang Nan's avatar
      perf record: Read from overwritable ring buffer · 05737464
      Wang Nan authored
      Drive the evlist->bkw_mmap_state state machine during draining and when
      SIGUSR2 is received. Read the backward ring buffer in record__mmap_read_all.
      Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
      Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Nilay Vaish <nilayvaish@gmail.com>
      Cc: Zefan Li <lizefan@huawei.com>
      Cc: pi3orama@163.com
      Link: http://lkml.kernel.org/r/1468485287-33422-12-git-send-email-wangnan0@huawei.comSigned-off-by: default avatarHe Kuang <hekuang@huawei.com>
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      05737464
    • Wang Nan's avatar
      perf evlist: Setup backward mmap state machine · 54cc54de
      Wang Nan authored
      Introduce a bkw_mmap_state state machine to evlist:
      
                           .________________(forbid)_____________.
                           |                                     V
       NOTREADY --(0)--> RUNNING --(1)--> DATA_PENDING --(2)--> EMPTY
                           ^  ^              |   ^               |
                           |  |__(forbid)____/   |___(forbid)___/|
                           |                                     |
                            \_________________(3)_______________/
      
       NOTREADY     : Backward ring buffers are not ready
       RUNNING      : Backward ring buffers are recording
       DATA_PENDING : We are required to collect data from backward ring buffers
       EMPTY        : We have collected data from backward ring buffers.
      
       (0): Setup backward ring buffer
       (1): Pause ring buffers for reading
       (2): Read from ring buffers
       (3): Resume ring buffers for recording
      
      We can't avoid this complexity. Since we deliberately drop records from
      overwritable ring buffer, there's no way for us to check remaining from
      ring buffer itself (by checking head and old pointers). Therefore, we
      need DATA_PENDING and EMPTY state to help us recording what we have done
      to the ring buffer.
      
      In record__mmap_read_evlist(), drive this state machine from DATA_PENDING
      to EMPTY.
      
      In perf_evlist__mmap_per_evsel(), drive this state machine from NOTREADY
      to RUNNING when creating backward mmap.
      Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
      Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
      Cc: He Kuang <hekuang@huawei.com>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Nilay Vaish <nilayvaish@gmail.com>
      Cc: Zefan Li <lizefan@huawei.com>
      Cc: pi3orama@163.com
      Link: http://lkml.kernel.org/r/1468485287-33422-11-git-send-email-wangnan0@huawei.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      54cc54de
    • Wang Nan's avatar
      perf evlist: Introduce backward_mmap array for evlist · b2cb615d
      Wang Nan authored
      Add backward_mmap to evlist, free it together with normal mmap.
      
      Improve perf_evlist__pick_pc(), search backward_mmap if evlist->mmap is
      not available.
      
      This patch doesn't alloc this array. It will be allocated conditionally
      in the following commits.
      Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
      Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
      Cc: He Kuang <hekuang@huawei.com>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Nilay Vaish <nilayvaish@gmail.com>
      Cc: Zefan Li <lizefan@huawei.com>
      Cc: pi3orama@163.com
      Link: http://lkml.kernel.org/r/1468485287-33422-8-git-send-email-wangnan0@huawei.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      b2cb615d
    • Wang Nan's avatar
      perf record: Decouple record__mmap_read() and evlist. · a4ea0ec4
      Wang Nan authored
      Perf evlist will have multiple mmap arrays. Update record__mmap_read():
      it should read from 'struct perf_mmap' directly.
      
      Also, make record__mmap_read() ready to read from backward ring buffer.
      Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
      Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
      Cc: He Kuang <hekuang@huawei.com>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Nilay Vaish <nilayvaish@gmail.com>
      Cc: Zefan Li <lizefan@huawei.com>
      Cc: pi3orama@163.com
      Link: http://lkml.kernel.org/r/1468485287-33422-5-git-send-email-wangnan0@huawei.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      a4ea0ec4
  3. 12 Jul, 2016 1 commit
    • Arnaldo Carvalho de Melo's avatar
      tools: Introduce str_error_r() · c8b5f2c9
      Arnaldo Carvalho de Melo authored
      The tools so far have been using the strerror_r() GNU variant, that
      returns a string, be it the buffer passed or something else.
      
      But that, besides being tricky in cases where we expect that the
      function using strerror_r() returns the error formatted in a provided
      buffer (we have to check if it returned something else and copy that
      instead), breaks the build on systems not using glibc, like Alpine
      Linux, where musl libc is used.
      
      So, introduce yet another wrapper, str_error_r(), that has the GNU
      interface, but uses the portable XSI variant of strerror_r(), so that
      users rest asured that the provided buffer is used and it is what is
      returned.
      
      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: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      c8b5f2c9
  4. 28 Jun, 2016 3 commits
  5. 23 Jun, 2016 2 commits
  6. 21 Jun, 2016 1 commit
  7. 30 May, 2016 1 commit
  8. 23 May, 2016 3 commits
  9. 28 Apr, 2016 5 commits
  10. 18 Apr, 2016 1 commit
  11. 15 Apr, 2016 1 commit
  12. 14 Apr, 2016 2 commits
  13. 11 Apr, 2016 2 commits
  14. 31 Mar, 2016 1 commit
    • Adrian Hunter's avatar
      perf tools: Add time conversion event · 46bc29b9
      Adrian Hunter authored
      Intel PT uses the time members from the perf_event_mmap_page to convert
      between TSC and perf time.
      
      Due to a lack of foresight when Intel PT was implemented, those time
      members were recorded in the (implementation dependent) AUXTRACE_INFO
      event, the structure of which is generally inaccessible outside of the
      Intel PT decoder.  However now the conversion between TSC and perf time
      is needed when processing a jitdump file when Intel PT has been used for
      tracing.
      
      So add a user event to record the time members.  'perf record' will
      synthesize the event if the information is available.  And session
      processing will put a copy of the event on the session so that tools
      like 'perf inject' can easily access it.
      Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Stephane Eranian <eranian@google.com>
      Link: http://lkml.kernel.org/r/1457426324-30158-1-git-send-email-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      46bc29b9
  15. 03 Mar, 2016 4 commits
  16. 22 Feb, 2016 1 commit
    • Wang Nan's avatar
      perf record: Apply config to BPF objects before recording · 8690a2a7
      Wang Nan authored
      bpf__apply_obj_config() is introduced as the core API to apply object
      config options to all BPF objects. This patch also does the real work
      for setting values for BPF_MAP_TYPE_PERF_ARRAY maps by inserting value
      stored in map's private field into the BPF map.
      
      This patch is required because we are not always able to set all BPF
      config during parsing. Further patch will set events created by perf to
      BPF_MAP_TYPE_PERF_EVENT_ARRAY maps, which is not exist until
      perf_evsel__open().
      
      bpf_map_foreach_key() is introduced to iterate over each key needs to be
      configured. This function would be extended to support more map types
      and different key settings.
      
      In perf record, before start recording, call bpf__apply_config() to turn
      on all BPF config options.
      
      Test result:
      
        # cat ./test_bpf_map_1.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 void *(*map_lookup_elem)(struct bpf_map_def *, void *) =
            (void *)BPF_FUNC_map_lookup_elem;
        static int (*trace_printk)(const char *fmt, int fmt_size, ...) =
            (void *)BPF_FUNC_trace_printk;
        struct bpf_map_def SEC("maps") channel = {
            .type = BPF_MAP_TYPE_ARRAY,
            .key_size = sizeof(int),
            .value_size = sizeof(int),
            .max_entries = 1,
        };
        SEC("func=sys_nanosleep")
        int func(void *ctx)
        {
            int key = 0;
            char fmt[] = "%d\n";
            int *pval = map_lookup_elem(&channel, &key);
            if (!pval)
                return 0;
            trace_printk(fmt, sizeof(fmt), *pval);
            return 0;
        }
        char _license[] SEC("license") = "GPL";
        int _version SEC("version") = LINUX_VERSION_CODE;
        /************************* END ***************************/
      
        # echo "" > /sys/kernel/debug/tracing/trace
        # ./perf record -e './test_bpf_map_1.c/map:channel.value=11/' usleep 10
        [ perf record: Woken up 1 times to write data ]
        [ perf record: Captured and wrote 0.012 MB perf.data ]
        # cat /sys/kernel/debug/tracing/trace
        # tracer: nop
        #
        # entries-in-buffer/entries-written: 1/1   #P:8
        [SNIP]
        #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
        #              | |       |   ||||       |         |
                   usleep-18593 [007] d... 2394714.395539: : 11
        # ./perf record -e './test_bpf_map_1.c/map:channel.value=101/' usleep 10
        [ perf record: Woken up 1 times to write data ]
        [ perf record: Captured and wrote 0.012 MB perf.data ]
        # cat /sys/kernel/debug/tracing/trace
        # tracer: nop
        #
        # entries-in-buffer/entries-written: 1/1   #P:8
        [SNIP]
        #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
        #              | |       |   ||||       |         |
                   usleep-18593 [007] d... 2394714.395539: : 11
                   usleep-19000 [006] d... 2394831.057840: : 101
      Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
      Tested-by: default avatarArnaldo 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: Jiri Olsa <jolsa@kernel.org>
      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/1456132275-98875-6-git-send-email-wangnan0@huawei.comSigned-off-by: default avatarHe Kuang <hekuang@huawei.com>
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      8690a2a7
  17. 18 Feb, 2016 1 commit
    • Jiri Olsa's avatar
      perf record: Add --all-user/--all-kernel options · 85723885
      Jiri Olsa authored
      Allow user to easily switch all events to user or kernel space with simple
      --all-user or --all-kernel options.
      
      This will be handy within perf mem/c2c wrappers to switch easily monitoring
      modes.
      
      Committer note:
      
      Testing it:
      
        # perf record --all-kernel --all-user -a sleep 2
         Error: option `all-user' cannot be used with all-kernel
         Usage: perf record [<options>] [<command>]
            or: perf record [<options>] -- <command> [<options>]
      
              --all-user        Configure all used events to run in user space.
              --all-kernel      Configure all used events to run in kernel space.
        # perf record --all-user --all-kernel -a sleep 2
         Error: option `all-kernel' cannot be used with all-user
         Usage: perf record [<options>] [<command>]
            or: perf record [<options>] -- <command> [<options>]
      
              --all-kernel      Configure all used events to run in kernel space.
              --all-user        Configure all used events to run in user space.
        # perf record --all-user -a sleep 1
        [ perf record: Woken up 1 times to write data ]
        [ perf record: Captured and wrote 1.416 MB perf.data (162 samples) ]
        # perf report | grep '\[k\]'
        # perf record --all-kernel -a sleep 1
        [ perf record: Woken up 1 times to write data ]
        [ perf record: Captured and wrote 1.423 MB perf.data (296 samples) ]
        # perf report | grep '\[\.\]'
        #
      Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
      Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Stephane Eranian <eranian@google.com>
      Link: http://lkml.kernel.org/r/1455525293-8671-2-git-send-email-jolsa@kernel.org
      [ Made those options to be mutually exclusive ]
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      85723885
  18. 29 Jan, 2016 1 commit
  19. 12 Jan, 2016 1 commit
  20. 08 Jan, 2016 1 commit
  21. 17 Dec, 2015 1 commit