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Groups > linux.kernel > #1374294
| From | Wang Nan <wangnan0@huawei.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 2/4] perf trace: Print content of bpf-output event |
| Date | 2016-04-08 17:10 +0200 |
| Message-ID | <rlGcP-5Mb-37@gated-at.bofh.it> (permalink) |
| References | <rlGcO-5Mb-13@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
With this patch the contend of BPF output event is printed by
'perf trace'. For example:
# ./perf trace -a --ev bpf-output/no-inherit,name=evt/ \
--ev ./test_bpf_trace.c/map:channel.event=evt/ \
usleep 100000
...
1.787 ( 0.004 ms): usleep/3832 nanosleep(rqtp: 0x7ffc78b18980 ) ...
1.787 ( ): evt:Raise a BPF event!..)
1.788 ( ): perf_bpf_probe:func_begin:(ffffffff810e97d0))
...
101.866 (87.038 ms): gmain/1654 poll(ufds: 0x7f57a80008c0, nfds: 2, timeout_msecs: 1000 ) ...
101.866 ( ): evt:Raise a BPF event!..)
101.867 ( ): perf_bpf_probe:func_end:(ffffffff810e97d0 <- ffffffff81796173))
101.869 (100.087 ms): usleep/3832 ... [continued]: nanosleep()) = 0
...
(There is an extra ')' at the end of several lines. However, it is
another problem, unrelated to this commit.)
Where test_bpf_trace.c is:
/************************ 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__,
};
static inline int __attribute__((always_inline))
func(void *ctx, int type)
{
char output_str[] = "Raise a BPF event!";
char err_str[] = "BAD %d\n";
int err;
err = perf_event_output(ctx, &channel, get_smp_processor_id(),
&output_str, sizeof(output_str));
if (err)
trace_printk(err_str, sizeof(err_str), err);
return 1;
}
SEC("func_begin=sys_nanosleep")
int func_begin(void *ctx) {return func(ctx, 1);}
SEC("func_end=sys_nanosleep%return")
int func_end(void *ctx) { return func(ctx, 2);}
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
/************************* END ***************************/
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: pi3orama@163.com
---
tools/perf/builtin-trace.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 6fbed86..fb8257f 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -2680,11 +2680,15 @@ out_enomem:
goto out;
}
-static int validate_evlist(struct perf_evlist *evlist)
+static int validate_evlist(struct perf_evlist *evlist, bool *has_bpf_output)
{
struct perf_evsel *evsel;
evlist__for_each(evlist, evsel) {
+ if (perf_evsel__is_bpf_output(evsel)) {
+ *has_bpf_output = true;
+ continue;
+ }
if (evsel->attr.type != PERF_TYPE_TRACEPOINT)
return -EINVAL;
}
@@ -3268,6 +3272,7 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
const char * const trace_subcommands[] = { "record", NULL };
int err;
char bf[BUFSIZ];
+ bool has_bpf_output = false;
signal(SIGSEGV, sighandler_dump_stack);
signal(SIGFPE, sighandler_dump_stack);
@@ -3284,12 +3289,12 @@ int cmd_trace(int argc, const char **argv, const char *prefix __maybe_unused)
argc = parse_options_subcommand(argc, argv, trace_options, trace_subcommands,
trace_usage, PARSE_OPT_STOP_AT_NON_OPTION);
- if (validate_evlist(trace.evlist)) {
- pr_err("Only support tracepoint events!\n");
+ if (validate_evlist(trace.evlist, &has_bpf_output)) {
+ pr_err("Only support tracepoint and bpf-output events!\n");
return -EINVAL;
}
- if (trace.trace_pgfaults) {
+ if (trace.trace_pgfaults || has_bpf_output) {
trace.opts.sample_address = true;
trace.opts.sample_time = true;
}
--
1.8.3.4
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[PATCH 0/4] perf bpf: Add __bpf_stdout__ support Wang Nan <wangnan0@huawei.com> - 2016-04-08 17:10 +0200
[PATCH 1/4] perf trace: Improve error message when receive non-tracepoint events Wang Nan <wangnan0@huawei.com> - 2016-04-08 17:10 +0200
Re: [PATCH 1/4] perf trace: Improve error message when receive non-tracepoint events Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-08 17:30 +0200
Re: [PATCH 1/4] perf trace: Improve error message when receive non-tracepoint events "Wangnan (F)" <wangnan0@huawei.com> - 2016-04-08 18:20 +0200
Re: [PATCH 1/4] perf trace: Improve error message when receive non-tracepoint events Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-08 19:40 +0200
[PATCH 2/4] perf trace: Print content of bpf-output event Wang Nan <wangnan0@huawei.com> - 2016-04-08 17:10 +0200
Re: [PATCH 2/4] perf trace: Print content of bpf-output event "Wangnan (F)" <wangnan0@huawei.com> - 2016-04-08 18:00 +0200
Re: [PATCH 2/4] perf trace: Print content of bpf-output event Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-08 19:30 +0200
[PATCH 3/4] perf bpf: Clone bpf stdout events in multiple bpf scripts Wang Nan <wangnan0@huawei.com> - 2016-04-08 17:20 +0200
Re: [PATCH 3/4] perf bpf: Clone bpf stdout events in multiple bpf scripts Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-08 19:40 +0200
[tip:perf/core] perf bpf: Clone bpf stdout events in multiple bpf scripts tip-bot for Wang Nan <tipbot@zytor.com> - 2016-04-13 09:30 +0200
[PATCH 4/4] perf bpf: Automatically create bpf-output event __bpf_stdout__ Wang Nan <wangnan0@huawei.com> - 2016-04-08 17:20 +0200
Re: [PATCH 4/4] perf bpf: Automatically create bpf-output event __bpf_stdout__ Arnaldo Carvalho de Melo <acme@kernel.org> - 2016-04-08 20:00 +0200
[tip:perf/core] perf bpf: Automatically create bpf-output event __bpf_stdout__ tip-bot for Wang Nan <tipbot@zytor.com> - 2016-04-13 09:30 +0200
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