* [PATCH] perf trace: Add --max-summary option
@ 2025-08-21 0:32 Namhyung Kim
2025-08-23 5:19 ` Howard Chu
0 siblings, 1 reply; 3+ messages in thread
From: Namhyung Kim @ 2025-08-21 0:32 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Ian Rogers, Kan Liang
Cc: Jiri Olsa, Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Howard Chu
The --max-summary option is to limit the number of output lines for
syscall summary stats. The max applies to each entries like thread and
cgroups. For total summary, it will just print up to the given number.
For example,
$ sudo perf trace -as --max-summary 3 sleep 0.1
ThreadPoolServi (1011651), 114 events, 14.8%
syscall calls errors total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- ------ -------- --------- --------- --------- ------
epoll_wait 38 0 95.589 0.000 2.515 11.153 28.98%
futex 9 0 0.040 0.002 0.004 0.014 28.63%
read 10 0 0.037 0.003 0.004 0.005 4.67%
sleep (1050529), 250 events, 32.4%
syscall calls errors total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- ------ -------- --------- --------- --------- ------
clock_nanosleep 1 0 100.156 100.156 100.156 100.156 0.00%
execve 4 3 1.020 0.005 0.255 0.989 95.93%
openat 36 17 0.416 0.003 0.012 0.029 10.58%
...
And this is for per-cgroup summary using BPF.
$ sudo perf trace -as --max-summary 3 --summary-mode=cgroup --bpf-summary sleep 0.1
cgroup /user.slice/user-657345.slice/user@657345.service/session.slice/org.gnome.Shell@x11.service, 12 events
syscall calls errors total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- ------ -------- --------- --------- --------- ------
recvmsg 8 7 0.016 0.001 0.002 0.006 39.73%
ppoll 1 0 0.014 0.014 0.014 0.014 0.00%
write 2 0 0.010 0.002 0.005 0.008 61.02%
cgroup /user.slice/user-657345.slice/session-4.scope, 73 events
syscall calls errors total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- ------ -------- --------- --------- --------- ------
epoll_wait 8 0 13.461 0.010 1.683 12.235 89.66%
ioctl 20 0 0.204 0.001 0.010 0.113 54.01%
writev 11 0 0.164 0.004 0.015 0.042 20.34%
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/Documentation/perf-trace.txt | 4 +++
tools/perf/builtin-trace.c | 10 ++++++-
tools/perf/util/bpf-trace-summary.c | 40 ++++++++++++++-----------
tools/perf/util/trace.h | 4 +--
4 files changed, 38 insertions(+), 20 deletions(-)
diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt
index 973fede403a05d2e..892c82a9bf402db2 100644
--- a/tools/perf/Documentation/perf-trace.txt
+++ b/tools/perf/Documentation/perf-trace.txt
@@ -249,6 +249,10 @@ the thread executes on the designated CPUs. Default is to monitor all CPUs.
works well with -s/--summary option where no argument information is
required.
+--max-summary=N::
+ Maximum number of lines in the summary mode. Note that this applies to
+ each entry (thread or cgroup).
+
PAGEFAULTS
----------
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index a7a49d8997d55594..2e205c661fc360a1 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -197,6 +197,7 @@ struct trace {
unsigned int max_stack;
unsigned int min_stack;
enum trace_summary_mode summary_mode;
+ int max_summary;
int raw_augmented_syscalls_args_size;
bool raw_augmented_syscalls;
bool fd_path_disabled;
@@ -4625,7 +4626,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
if (!err) {
if (trace->summary) {
if (trace->summary_bpf)
- trace_print_bpf_summary(trace->output);
+ trace_print_bpf_summary(trace->output, trace->max_summary);
else if (trace->summary_mode == SUMMARY__BY_TOTAL)
trace__fprintf_total_summary(trace, trace->output);
else
@@ -4848,6 +4849,7 @@ static size_t syscall__dump_stats(struct trace *trace, int e_machine, FILE *fp,
struct hashmap *syscall_stats)
{
size_t printed = 0;
+ int lines = 0;
struct syscall *sc;
struct syscall_entry *entries;
@@ -4892,7 +4894,11 @@ static size_t syscall__dump_stats(struct trace *trace, int e_machine, FILE *fp,
fprintf(fp, "\t\t\t\t%s: %d\n", perf_env__arch_strerrno(trace->host->env, e + 1), stats->errnos[e]);
}
}
+ lines++;
}
+
+ if (trace->max_summary && trace->max_summary <= lines)
+ break;
}
free(entries);
@@ -5469,6 +5475,8 @@ int cmd_trace(int argc, const char **argv)
OPT_BOOLEAN(0, "force-btf", &trace.force_btf, "Prefer btf_dump general pretty printer"
"to customized ones"),
OPT_BOOLEAN(0, "bpf-summary", &trace.summary_bpf, "Summary syscall stats in BPF"),
+ OPT_INTEGER(0, "max-summary", &trace.max_summary,
+ "Max number of entries in the summary."),
OPTS_EVSWITCH(&trace.evswitch),
OPT_END()
};
diff --git a/tools/perf/util/bpf-trace-summary.c b/tools/perf/util/bpf-trace-summary.c
index 69fb165da206b01f..8dfe7e678941d0d8 100644
--- a/tools/perf/util/bpf-trace-summary.c
+++ b/tools/perf/util/bpf-trace-summary.c
@@ -138,11 +138,14 @@ static bool sc_node_equal(long key1, long key2, void *ctx __maybe_unused)
return key1 == key2;
}
-static int print_common_stats(struct syscall_data *data, FILE *fp)
+static int print_common_stats(struct syscall_data *data, int max_summary, FILE *fp)
{
int printed = 0;
- for (int i = 0; i < data->nr_nodes; i++) {
+ if (max_summary == 0 || max_summary > data->nr_nodes)
+ max_summary = data->nr_nodes;
+
+ for (int i = 0; i < max_summary; i++) {
struct syscall_node *node = &data->nodes[i];
struct syscall_stats *stat = &node->stats;
double total = (double)(stat->total_time) / NSEC_PER_MSEC;
@@ -200,7 +203,7 @@ static int update_thread_stats(struct hashmap *hash, struct syscall_key *map_key
return 0;
}
-static int print_thread_stat(struct syscall_data *data, FILE *fp)
+static int print_thread_stat(struct syscall_data *data, int max_summary, FILE *fp)
{
int printed = 0;
@@ -213,18 +216,18 @@ static int print_thread_stat(struct syscall_data *data, FILE *fp)
printed += fprintf(fp, " (msec) (msec) (msec) (msec) (%%)\n");
printed += fprintf(fp, " --------------- -------- ------ -------- --------- --------- --------- ------\n");
- printed += print_common_stats(data, fp);
+ printed += print_common_stats(data, max_summary, fp);
printed += fprintf(fp, "\n\n");
return printed;
}
-static int print_thread_stats(struct syscall_data **data, int nr_data, FILE *fp)
+static int print_thread_stats(struct syscall_data **data, int nr_data, int max_summary, FILE *fp)
{
int printed = 0;
for (int i = 0; i < nr_data; i++)
- printed += print_thread_stat(data[i], fp);
+ printed += print_thread_stat(data[i], max_summary, fp);
return printed;
}
@@ -277,7 +280,7 @@ static int update_total_stats(struct hashmap *hash, struct syscall_key *map_key,
return 0;
}
-static int print_total_stats(struct syscall_data **data, int nr_data, FILE *fp)
+static int print_total_stats(struct syscall_data **data, int nr_data, int max_summary, FILE *fp)
{
int printed = 0;
int nr_events = 0;
@@ -291,8 +294,11 @@ static int print_total_stats(struct syscall_data **data, int nr_data, FILE *fp)
printed += fprintf(fp, " (msec) (msec) (msec) (msec) (%%)\n");
printed += fprintf(fp, " --------------- -------- ------ -------- --------- --------- --------- ------\n");
- for (int i = 0; i < nr_data; i++)
- printed += print_common_stats(data[i], fp);
+ if (max_summary == 0 || max_summary > nr_data)
+ max_summary = nr_data;
+
+ for (int i = 0; i < max_summary; i++)
+ printed += print_common_stats(data[i], max_summary, fp);
printed += fprintf(fp, "\n\n");
return printed;
@@ -333,7 +339,7 @@ static int update_cgroup_stats(struct hashmap *hash, struct syscall_key *map_key
return 0;
}
-static int print_cgroup_stat(struct syscall_data *data, FILE *fp)
+static int print_cgroup_stat(struct syscall_data *data, int max_summary, FILE *fp)
{
int printed = 0;
struct cgroup *cgrp = __cgroup__find(&cgroups, data->key);
@@ -351,23 +357,23 @@ static int print_cgroup_stat(struct syscall_data *data, FILE *fp)
printed += fprintf(fp, " (msec) (msec) (msec) (msec) (%%)\n");
printed += fprintf(fp, " --------------- -------- ------ -------- --------- --------- --------- ------\n");
- printed += print_common_stats(data, fp);
+ printed += print_common_stats(data, max_summary, fp);
printed += fprintf(fp, "\n\n");
return printed;
}
-static int print_cgroup_stats(struct syscall_data **data, int nr_data, FILE *fp)
+static int print_cgroup_stats(struct syscall_data **data, int nr_data, int max_summary, FILE *fp)
{
int printed = 0;
for (int i = 0; i < nr_data; i++)
- printed += print_cgroup_stat(data[i], fp);
+ printed += print_cgroup_stat(data[i], max_summary, fp);
return printed;
}
-int trace_print_bpf_summary(FILE *fp)
+int trace_print_bpf_summary(FILE *fp, int max_summary)
{
struct bpf_map *map = skel->maps.syscall_stats_map;
struct syscall_key *prev_key, key;
@@ -420,13 +426,13 @@ int trace_print_bpf_summary(FILE *fp)
switch (skel->rodata->aggr_mode) {
case SYSCALL_AGGR_THREAD:
- printed += print_thread_stats(data, nr_data, fp);
+ printed += print_thread_stats(data, nr_data, max_summary, fp);
break;
case SYSCALL_AGGR_CPU:
- printed += print_total_stats(data, nr_data, fp);
+ printed += print_total_stats(data, nr_data, max_summary, fp);
break;
case SYSCALL_AGGR_CGROUP:
- printed += print_cgroup_stats(data, nr_data, fp);
+ printed += print_cgroup_stats(data, nr_data, max_summary, fp);
break;
default:
break;
diff --git a/tools/perf/util/trace.h b/tools/perf/util/trace.h
index fa8d480527a22cef..fbbcfe6f44fe05ca 100644
--- a/tools/perf/util/trace.h
+++ b/tools/perf/util/trace.h
@@ -16,7 +16,7 @@ enum trace_summary_mode {
int trace_prepare_bpf_summary(enum trace_summary_mode mode);
void trace_start_bpf_summary(void);
void trace_end_bpf_summary(void);
-int trace_print_bpf_summary(FILE *fp);
+int trace_print_bpf_summary(FILE *fp, int max_summary);
void trace_cleanup_bpf_summary(void);
#else /* !HAVE_BPF_SKEL */
@@ -27,7 +27,7 @@ static inline int trace_prepare_bpf_summary(enum trace_summary_mode mode __maybe
}
static inline void trace_start_bpf_summary(void) {}
static inline void trace_end_bpf_summary(void) {}
-static inline int trace_print_bpf_summary(FILE *fp __maybe_unused)
+static inline int trace_print_bpf_summary(FILE *fp __maybe_unused, int max_summary __maybe_unused)
{
return 0;
}
--
2.51.0.rc1.193.gad69d77794-goog
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] perf trace: Add --max-summary option
2025-08-21 0:32 [PATCH] perf trace: Add --max-summary option Namhyung Kim
@ 2025-08-23 5:19 ` Howard Chu
2025-09-12 19:45 ` Arnaldo Carvalho de Melo
0 siblings, 1 reply; 3+ messages in thread
From: Howard Chu @ 2025-08-23 5:19 UTC (permalink / raw)
To: Namhyung Kim
Cc: Arnaldo Carvalho de Melo, Ian Rogers, Kan Liang, Jiri Olsa,
Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users
Hello Namhyung,
On Wed, Aug 20, 2025 at 5:32 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> The --max-summary option is to limit the number of output lines for
> syscall summary stats. The max applies to each entries like thread and
> cgroups. For total summary, it will just print up to the given number.
>
> For example,
>
> $ sudo perf trace -as --max-summary 3 sleep 0.1
>
> ThreadPoolServi (1011651), 114 events, 14.8%
>
> syscall calls errors total min avg max stddev
> (msec) (msec) (msec) (msec) (%)
> --------------- -------- ------ -------- --------- --------- --------- ------
> epoll_wait 38 0 95.589 0.000 2.515 11.153 28.98%
> futex 9 0 0.040 0.002 0.004 0.014 28.63%
> read 10 0 0.037 0.003 0.004 0.005 4.67%
>
> sleep (1050529), 250 events, 32.4%
>
> syscall calls errors total min avg max stddev
> (msec) (msec) (msec) (msec) (%)
> --------------- -------- ------ -------- --------- --------- --------- ------
> clock_nanosleep 1 0 100.156 100.156 100.156 100.156 0.00%
> execve 4 3 1.020 0.005 0.255 0.989 95.93%
> openat 36 17 0.416 0.003 0.012 0.029 10.58%
>
> ...
>
> And this is for per-cgroup summary using BPF.
>
> $ sudo perf trace -as --max-summary 3 --summary-mode=cgroup --bpf-summary sleep 0.1
>
> cgroup /user.slice/user-657345.slice/user@657345.service/session.slice/org.gnome.Shell@x11.service, 12 events
>
> syscall calls errors total min avg max stddev
> (msec) (msec) (msec) (msec) (%)
> --------------- -------- ------ -------- --------- --------- --------- ------
> recvmsg 8 7 0.016 0.001 0.002 0.006 39.73%
> ppoll 1 0 0.014 0.014 0.014 0.014 0.00%
> write 2 0 0.010 0.002 0.005 0.008 61.02%
>
> cgroup /user.slice/user-657345.slice/session-4.scope, 73 events
>
> syscall calls errors total min avg max stddev
> (msec) (msec) (msec) (msec) (%)
> --------------- -------- ------ -------- --------- --------- --------- ------
> epoll_wait 8 0 13.461 0.010 1.683 12.235 89.66%
> ioctl 20 0 0.204 0.001 0.010 0.113 54.01%
> writev 11 0 0.164 0.004 0.015 0.042 20.34%
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Howard Chu <howardchu95@gmail.com>
Thanks,
Haowei
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] perf trace: Add --max-summary option
2025-08-23 5:19 ` Howard Chu
@ 2025-09-12 19:45 ` Arnaldo Carvalho de Melo
0 siblings, 0 replies; 3+ messages in thread
From: Arnaldo Carvalho de Melo @ 2025-09-12 19:45 UTC (permalink / raw)
To: Howard Chu
Cc: Namhyung Kim, Ian Rogers, Kan Liang, Jiri Olsa, Adrian Hunter,
Peter Zijlstra, Ingo Molnar, LKML, linux-perf-users
On Fri, Aug 22, 2025 at 10:19:26PM -0700, Howard Chu wrote:
> On Wed, Aug 20, 2025 at 5:32 PM Namhyung Kim <namhyung@kernel.org> wrote:
> Reviewed-by: Howard Chu <howardchu95@gmail.com>
Thanks, applied to perf-tools-next,
- Arnaldo
^ permalink raw reply [flat|nested] 3+ messages in thread
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