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author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-05-04 21:59:16 +0300 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2018-05-15 20:31:24 +0300 |
commit | d8fc764d0b39c912de510b50102b60a64882223e (patch) | |
tree | 8ffbda5a7322abf331f4aae229a980be5283c909 /tools/perf/include/bpf | |
parent | 1f477305ab462e2fd1fa8a4c4fa425ad752b3175 (diff) | |
download | linux-d8fc764d0b39c912de510b50102b60a64882223e.tar.xz |
perf bpf: Add probe() helper to reduce kprobes boilerplate
So that kprobe definitions become:
int probe(function, variables)(void *ctx, int err, var1, var2, ...)
The existing 5sec.c, got converted and goes from:
SEC("func=hrtimer_nanosleep rqtp->tv_sec")
int func(void *ctx, int err, long sec)
{
}
To:
int probe(hrtimer_nanosleep, rqtp->tv_sec)(void *ctx, int err, long sec)
{
}
If we decide to add tv_nsec as well, then it becomes:
$ cat tools/perf/examples/bpf/5sec.c
#include <bpf.h>
int probe(hrtimer_nanosleep, rqtp->tv_sec rqtp->tv_nsec)(void *ctx, int err, long sec, long nsec)
{
return sec == 5;
}
license(GPL);
$
And if we run it, system wide as before and run some 'sleep' with values
for the tv_nsec field, we get:
# perf trace --no-syscalls -e tools/perf/examples/bpf/5sec.c
0.000 perf_bpf_probe:hrtimer_nanosleep:(ffffffff9811b5f0) tv_sec=5 tv_nsec=100000000
9641.650 perf_bpf_probe:hrtimer_nanosleep:(ffffffff9811b5f0) tv_sec=5 tv_nsec=123450001
^C#
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-1v9r8f6ds5av0w9pcwpeknyl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/include/bpf')
-rw-r--r-- | tools/perf/include/bpf/bpf.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/perf/include/bpf/bpf.h b/tools/perf/include/bpf/bpf.h index cdfd18b9c318..dd764ad5efdf 100644 --- a/tools/perf/include/bpf/bpf.h +++ b/tools/perf/include/bpf/bpf.h @@ -3,6 +3,9 @@ #define _PERF_BPF_H #define SEC(NAME) __attribute__((section(NAME), used)) +#define probe(function, vars) \ + SEC(#function "=" #function " " #vars) function + #define license(name) \ char _license[] SEC("license") = #name; \ int _version SEC("version") = LINUX_VERSION_CODE; |