lkml.org 
[lkml]   [2016]   [Jan]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 25/53] perf tools: Introduce bpf-output event
    Date
    Commit a43eec304259a6c637f4014a6d4767159b6a3aa3 (bpf: introduce
    bpf_perf_event_output() helper) add a helper to enable BPF program
    output data to perf ring buffer through a new type of perf event
    PERF_COUNT_SW_BPF_OUTPUT. This patch enable perf to create perf
    event of that type. Now perf user can use following cmdline to
    receive output data from BPF programs:

    # ./perf record -a -e evt=bpf-output/no-inherit/ \
    -e ./test_bpf_output.c/maps:channel.event=evt/ ls /
    # ./perf script
    perf 12927 [004] 355971.129276: 0 evt=bpf-output/no-inherit/: ffffffff811ed5f1 sys_write
    perf 12927 [004] 355971.129279: 0 evt=bpf-output/no-inherit/: ffffffff811ed5f1 sys_write
    ...

    Test result:
    # cat ./test_bpf_output.c
    /************************ BEGIN **************************/
    #include <uapi/linux/bpf.h>
    struct bpf_map_def {
    unsigned int type;
    unsigned int key_size;
    unsigned int value_size;
    unsigned int max_entries;
    };

    #define SEC(NAME) __attribute__((section(NAME), used))
    static u64 (*ktime_get_ns)(void) =
    (void *)BPF_FUNC_ktime_get_ns;
    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_output)(void *, struct bpf_map_def *, int, void *, unsigned long) =
    (void *)BPF_FUNC_perf_event_output;

    struct bpf_map_def SEC("maps") channel = {
    .type = BPF_MAP_TYPE_PERF_EVENT_ARRAY,
    .key_size = sizeof(int),
    .value_size = sizeof(u32),
    .max_entries = __NR_CPUS__,
    };

    SEC("func_write=sys_write")
    int func_write(void *ctx)
    {
    struct {
    u64 ktime;
    int cpuid;
    } __attribute__((packed)) output_data;
    char error_data[] = "Error: failed to output: %d\n";

    output_data.cpuid = get_smp_processor_id();
    output_data.ktime = ktime_get_ns();
    int err = perf_event_output(ctx, &channel, get_smp_processor_id(),
    &output_data, sizeof(output_data));
    if (err)
    trace_printk(error_data, sizeof(error_data), err);
    return 0;
    }
    char _license[] SEC("license") = "GPL";
    int _version SEC("version") = LINUX_VERSION_CODE;
    /************************ END ***************************/

    # ./perf record -a -e evt=bpf-output/no-inherit/ \
    -e ./test_bpf_output.c/maps:channel.event=evt/ ls /
    # ./perf script | grep ls
    ls 4085 [000] 2746114.230215: evt=bpf-output/no-inherit/: ffffffff811ed5f1 sys_write (/lib/modules/4.3.0-rc4+/build/vmlinux)
    ls 4085 [000] 2746114.230244: evt=bpf-output/no-inherit/: ffffffff811ed5f1 sys_write (/lib/modules/4.3.0-rc4+/build/vmlinux)

    Signed-off-by: Wang Nan <wangnan0@huawei.com>
    Cc: Alexei Starovoitov <ast@kernel.org>
    Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
    Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
    Cc: David S. Miller <davem@davemloft.net>
    Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Zefan Li <lizefan@huawei.com>
    Cc: pi3orama@163.com
    ---
    tools/perf/util/bpf-loader.c | 5 ++---
    tools/perf/util/evsel.c | 5 +++++
    tools/perf/util/evsel.h | 8 ++++++++
    tools/perf/util/parse-events.l | 1 +
    4 files changed, 16 insertions(+), 3 deletions(-)

    diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
    index 6c25de8..92b815e 100644
    --- a/tools/perf/util/bpf-loader.c
    +++ b/tools/perf/util/bpf-loader.c
    @@ -1312,13 +1312,12 @@ apply_config_evsel_for_key(const char *name, int map_fd, void *pkey,
    return -BPF_LOADER_ERRNO__OBJCONF_MAP_EVTINH;
    }

    + if (perf_evsel__is_bpf_output(evsel))
    + check_pass = true;
    if (attr->type == PERF_TYPE_RAW)
    check_pass = true;
    if (attr->type == PERF_TYPE_HARDWARE)
    check_pass = true;
    - if (attr->type == PERF_TYPE_SOFTWARE &&
    - attr->config == PERF_COUNT_SW_BPF_OUTPUT)
    - check_pass = true;
    if (!check_pass) {
    pr_debug("ERROR: Event type is wrong for map %s\n", name);
    return -BPF_LOADER_ERRNO__OBJCONF_MAP_EVTTYPE;
    diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
    index a6b3b07..f1b633e 100644
    --- a/tools/perf/util/evsel.c
    +++ b/tools/perf/util/evsel.c
    @@ -225,6 +225,11 @@ struct perf_evsel *perf_evsel__new_idx(struct perf_event_attr *attr, int idx)
    if (evsel != NULL)
    perf_evsel__init(evsel, attr, idx);

    + if (perf_evsel__is_bpf_output(evsel)) {
    + evsel->attr.sample_type |= PERF_SAMPLE_RAW;
    + evsel->attr.sample_period = 1;
    + }
    +
    return evsel;
    }

    diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
    index 19885fb..022fcff 100644
    --- a/tools/perf/util/evsel.h
    +++ b/tools/perf/util/evsel.h
    @@ -365,6 +365,14 @@ static inline bool perf_evsel__is_function_event(struct perf_evsel *evsel)
    #undef FUNCTION_EVENT
    }

    +static inline bool perf_evsel__is_bpf_output(struct perf_evsel *evsel)
    +{
    + struct perf_event_attr *attr = &evsel->attr;
    +
    + return (attr->config == PERF_COUNT_SW_BPF_OUTPUT) &&
    + (attr->type == PERF_TYPE_SOFTWARE);
    +}
    +
    struct perf_attr_details {
    bool freq;
    bool verbose;
    diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
    index 8bb3437..27d567f 100644
    --- a/tools/perf/util/parse-events.l
    +++ b/tools/perf/util/parse-events.l
    @@ -249,6 +249,7 @@ cpu-migrations|migrations { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COU
    alignment-faults { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_ALIGNMENT_FAULTS); }
    emulation-faults { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_EMULATION_FAULTS); }
    dummy { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_DUMMY); }
    +bpf-output { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_BPF_OUTPUT); }

    /*
    * We have to handle the kernel PMU event cycles-ct/cycles-t/mem-loads/mem-stores separately.
    --
    1.8.3.4
    \
     
     \ /
      Last update: 2016-01-11 15:41    [W:7.132 / U:0.180 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site