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Message-ID: <1436513770-8896-2-git-send-email-wangnan0@huawei.com>
Date: Fri, 10 Jul 2015 07:36:10 +0000
From: Wang Nan <wangnan0@...wei.com>
To: <acme@...nel.org>, <rostedt@...dmis.org>, <ak@...ux.intel.com>,
<brendan.d.gregg@...il.com>
CC: <lizefan@...wei.com>, <linux-kernel@...r.kernel.org>,
<pi3orama@....com>
Subject: [PATCH 2/2] perf record: Allow passing perf's own pid to '--filter'
This patch allows 'perf record' to exclude events issued by perf itself
by '--exclude-perf' option.
Before this patch, when doing something like:
# perf record -a -e syscalls:sys_enter_write <cmd>
One could easily get result like this:
# /tmp/perf report --stdio
...
# Overhead Command Shared Object Symbol
# ........ ....... .................. ....................
#
99.99% perf libpthread-2.18.so [.] __write_nocancel
0.01% ls libc-2.18.so [.] write
0.01% sshd libc-2.18.so [.] write
...
Where most events are generated by perf itself.
A shell trick can be done to filter perf itself out:
# cat << EOF > ./tmp
> #!/bin/sh
> exec perf record -e ... --filter="common_pid != \$\$" -a sleep 10
> EOF
# chmod a+x ./tmp
# ./tmp
However, doing so is user unfriendly.
This patch extracts evsel iteration framework introduced by patch 'perf
record: Apply filter to all events in a glob matching' into
foreach_evsel_in_last_glob(), and makes exclude_perf() function append
new filter expression to each evsel selected by a '-e' selector.
To avoid losing filters if user pass '--filter' after '--exclude-perf',
this patch uses perf_evsel__append_filter() in both case, instead of
perf_evsel__set_filter() which removes old filter. As a side effect, now
it is possible to use multiple '--filter' option for one selector. They
are combinded with '&&'.
Signed-off-by: Wang Nan <wangnan0@...wei.com>
---
tools/perf/Documentation/perf-record.txt | 11 ++++-
tools/perf/builtin-record.c | 3 ++
tools/perf/util/parse-events.c | 83 +++++++++++++++++++++++++++-----
tools/perf/util/parse-events.h | 1 +
4 files changed, 84 insertions(+), 14 deletions(-)
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 9b9d9d0..cb5ca6d 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -61,7 +61,16 @@ OPTIONS
"perf report" to view group events together.
--filter=<filter>::
- Event filter.
+ Event filter. This option should follow a event selector (-e) which
+ selects tracepoint event(s). Multiple '--filter' options are combined
+ using '&&'.
+
+--exclude-perf::
+ Don't record events issued by perf itself. This option should follow
+ a event selector (-e) which selects tracepoint event(s). It adds a
+ filter expression 'common_pid != $PERFPID' to filters. If other
+ '--filter' exists, the new filter expression will be combined with
+ them by '&&'.
-a::
--all-cpus::
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 283fe96..1932e27 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -992,6 +992,9 @@ struct option __record_options[] = {
parse_events_option),
OPT_CALLBACK(0, "filter", &record.evlist, "filter",
"event filter", parse_filter),
+ OPT_CALLBACK_NOOPT(0, "exclude-perf", &record.evlist,
+ NULL, "don't record events from perf itself",
+ exclude_perf),
OPT_STRING('p', "pid", &record.opts.target.pid, "pid",
"record events on existing process id"),
OPT_STRING('t', "tid", &record.opts.target.tid, "tid",
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index bbb7fbc..4f807fc 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1167,27 +1167,24 @@ int parse_events_option(const struct option *opt, const char *str,
return ret;
}
-int parse_filter(const struct option *opt, const char *str,
- int unset __maybe_unused)
+static int
+foreach_evsel_in_last_glob(struct perf_evlist *evlist,
+ int (*func)(struct perf_evsel *evsel,
+ const void *arg),
+ const void *arg)
{
- struct perf_evlist *evlist = *(struct perf_evlist **)opt->value;
struct perf_evsel *last = NULL;
+ int err;
if (evlist->nr_entries > 0)
last = perf_evlist__last(evlist);
do {
- if (last == NULL || last->attr.type != PERF_TYPE_TRACEPOINT) {
- fprintf(stderr,
- "--filter option should follow a -e tracepoint option\n");
- return -1;
- }
-
- if (perf_evsel__set_filter(last, str) < 0) {
- fprintf(stderr,
- "not enough memory to hold filter string\n");
+ err = (*func)(last, arg);
+ if (err)
return -1;
- }
+ if (!last)
+ return 0;
if (last->node.prev == &evlist->entries)
return 0;
@@ -1197,6 +1194,66 @@ int parse_filter(const struct option *opt, const char *str,
return 0;
}
+static int set_filter(struct perf_evsel *evsel, const void *arg)
+{
+ const char *str = arg;
+
+ if (evsel == NULL || evsel->attr.type != PERF_TYPE_TRACEPOINT) {
+ fprintf(stderr,
+ "--filter option should follow a -e tracepoint option\n");
+ return -1;
+ }
+
+ if (perf_evsel__append_filter(evsel, "&&", str) < 0) {
+ fprintf(stderr,
+ "not enough memory to hold filter string\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+int parse_filter(const struct option *opt, const char *str,
+ int unset __maybe_unused)
+{
+ struct perf_evlist *evlist = *(struct perf_evlist **)opt->value;
+
+ return foreach_evsel_in_last_glob(evlist, set_filter,
+ (const void *)str);
+}
+
+static int add_exclude_perf_filter(struct perf_evsel *evsel,
+ const void *arg __maybe_unused)
+{
+ char new_filter[64];
+
+ if (evsel == NULL || evsel->attr.type != PERF_TYPE_TRACEPOINT) {
+ fprintf(stderr,
+ "--exclude-perf option should follow a -e tracepoint option\n");
+ return -1;
+ }
+
+ snprintf(new_filter, sizeof(new_filter), "common_pid != %d", getpid());
+
+ if (perf_evsel__append_filter(evsel, "&&", new_filter) < 0) {
+ fprintf(stderr,
+ "not enough memory to hold filter string\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+int exclude_perf(const struct option *opt,
+ const char *arg __maybe_unused,
+ int unset __maybe_unused)
+{
+ struct perf_evlist *evlist = *(struct perf_evlist **)opt->value;
+
+ return foreach_evsel_in_last_glob(evlist, add_exclude_perf_filter,
+ NULL);
+}
+
static const char * const event_type_descriptors[] = {
"Hardware event",
"Software event",
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 131f29b..2063048 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -34,6 +34,7 @@ extern int parse_events(struct perf_evlist *evlist, const char *str,
struct parse_events_error *error);
extern int parse_events_terms(struct list_head *terms, const char *str);
extern int parse_filter(const struct option *opt, const char *str, int unset);
+extern int exclude_perf(const struct option *opt, const char *arg, int unset);
#define EVENTS_HELP_MAX (128*1024)
--
1.8.3.4
--
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