diff options
| author | Ian Rogers <irogers@google.com> | 2024-05-24 13:52:27 -0700 |
|---|---|---|
| committer | Namhyung Kim <namhyung@kernel.org> | 2024-05-30 10:05:57 -0700 |
| commit | af752016340021d433a962063067e819dba889b1 (patch) | |
| tree | 4cfbd4d243d26cffcf9955d15c72f3ad2d278805 | |
| parent | d92aa899fe0a66350303a1986d6dc7ec4b3a1ea7 (diff) | |
perf top: Allow filters on events
Allow filters to be added to perf top events. One use is to workaround
issues with:
```
$ perf top --uid="$(id -u)"
```
which tries to scan /proc find processes belonging to the uid and can
fail in such a pid terminates between the scan and the
perf_event_open reporting:
```
Error:
The sys_perf_event_open() syscall returned with 3 (No such process) for event (cycles:P).
/bin/dmesg | grep -i perf may provide additional information.
```
A similar filter:
```
$ perf top -e cycles:P --filter "uid == $(id -u)"
```
doesn't fail this way.
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240524205227.244375-4-irogers@google.com
| -rw-r--r-- | tools/perf/Documentation/perf-top.txt | 4 | ||||
| -rw-r--r-- | tools/perf/builtin-top.c | 9 |
2 files changed, 13 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt index a754875fa5bb..667e5102075e 100644 --- a/tools/perf/Documentation/perf-top.txt +++ b/tools/perf/Documentation/perf-top.txt @@ -43,6 +43,10 @@ Default is to monitor all CPUS. encoding with the layout of the event control registers as described by entries in /sys/bus/event_source/devices/cpu/format/*. +--filter=<filter>:: + Event filter. This option should follow an event selector (-e). For + syntax see linkperf:perf-record[1]. + -E <entries>:: --entries=<entries>:: Display this many functions. diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 1d6aef51c122..e8cbbf10d361 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -1055,6 +1055,13 @@ try_again: } } + if (evlist__apply_filters(evlist, &counter)) { + pr_err("failed to set filter \"%s\" on event %s with %d (%s)\n", + counter->filter ?: "BPF", evsel__name(counter), errno, + str_error_r(errno, msg, sizeof(msg))); + goto out_err; + } + if (evlist__mmap(evlist, opts->mmap_pages) < 0) { ui__error("Failed to mmap with %d (%s)\n", errno, str_error_r(errno, msg, sizeof(msg))); @@ -1462,6 +1469,8 @@ int cmd_top(int argc, const char **argv) OPT_CALLBACK('e', "event", &parse_events_option_args, "event", "event selector. use 'perf list' to list available events", parse_events_option), + OPT_CALLBACK(0, "filter", &top.evlist, "filter", + "event filter", parse_filter), OPT_U64('c', "count", &opts->user_interval, "event period to sample"), OPT_STRING('p', "pid", &target->pid, "pid", "profile events on existing process id"), |