From: Ian Rogers <irogers@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Kan Liang <kan.liang@linux.intel.com>,
Changbin Du <changbin.du@huawei.com>,
John Fastabend <john.fastabend@gmail.com>,
Andrii Nakryiko <andrii@kernel.org>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
bpf@vger.kernel.org
Subject: [PATCH v2 3/3] perf top: Allow filters on events
Date: Mon, 20 May 2024 18:04:39 -0700 [thread overview]
Message-ID: <20240521010439.321264-4-irogers@google.com> (raw)
In-Reply-To: <20240521010439.321264-1-irogers@google.com>
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>
---
tools/perf/Documentation/perf-top.txt | 4 ++++
tools/perf/builtin-top.c | 9 +++++++++
2 files changed, 13 insertions(+)
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 @@ static int perf_top__start_counters(struct perf_top *top)
}
}
+ 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"),
--
2.45.0.rc1.225.g2a3ae87e7f-goog
next prev parent reply other threads:[~2024-05-21 1:04 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-21 1:04 [PATCH v2 0/3] Use BPF filters for a "perf top -u" workaround Ian Rogers
2024-05-21 1:04 ` [PATCH v2 1/3] perf bpf filter: Give terms their own enum Ian Rogers
2024-05-21 1:04 ` [PATCH v2 2/3] perf bpf filter: Add uid and gid terms Ian Rogers
2024-05-21 1:04 ` Ian Rogers [this message]
2024-05-23 4:38 ` [PATCH v2 0/3] Use BPF filters for a "perf top -u" workaround Namhyung Kim
2024-05-24 17:58 ` Namhyung Kim
2024-05-24 20:22 ` Ian Rogers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240521010439.321264-4-irogers@google.com \
--to=irogers@google.com \
--cc=acme@kernel.org \
--cc=adrian.hunter@intel.com \
--cc=alexander.shishkin@linux.intel.com \
--cc=andrii@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=changbin.du@huawei.com \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=kan.liang@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).