@@ -1198,7 +1198,7 @@ SKELETONS += $(SKEL_OUT)/bperf_leader.skel.h $(SKEL_OUT)/bperf_follower.skel.h
SKELETONS += $(SKEL_OUT)/bperf_cgroup.skel.h $(SKEL_OUT)/func_latency.skel.h
SKELETONS += $(SKEL_OUT)/off_cpu.skel.h $(SKEL_OUT)/lock_contention.skel.h
SKELETONS += $(SKEL_OUT)/kwork_trace.skel.h $(SKEL_OUT)/sample_filter.skel.h
-SKELETONS += $(SKEL_OUT)/kwork_top.skel.h
+SKELETONS += $(SKEL_OUT)/kwork_top.skel.h $(SKEL_OUT)/syscall_summary.skel.h
SKELETONS += $(SKEL_OUT)/bench_uprobe.skel.h
SKELETONS += $(SKEL_OUT)/augmented_raw_syscalls.skel.h
@@ -55,6 +55,7 @@
#include "util/thread_map.h"
#include "util/stat.h"
#include "util/tool.h"
+#include "util/trace.h"
#include "util/util.h"
#include "trace/beauty/beauty.h"
#include "trace-event.h"
@@ -222,6 +223,7 @@ struct trace {
bool force;
bool vfs_getname;
bool force_btf;
+ bool summary_bpf;
int trace_pgfaults;
char *perfconfig_events;
struct {
@@ -4276,6 +4278,13 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
trace->live = true;
+ if (trace->summary_bpf) {
+ if (trace_prepare_bpf_summary() < 0)
+ goto out_delete_evlist;
+
+ goto create_maps;
+ }
+
if (!trace->raw_augmented_syscalls) {
if (trace->trace_syscalls && trace__add_syscall_newtp(trace))
goto out_error_raw_syscalls;
@@ -4334,6 +4343,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
if (trace->cgroup)
evlist__set_default_cgroup(trace->evlist, trace->cgroup);
+create_maps:
err = evlist__create_maps(evlist, &trace->opts.target);
if (err < 0) {
fprintf(trace->output, "Problems parsing the target to trace, check your options!\n");
@@ -4426,9 +4436,11 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
if (err < 0)
goto out_error_apply_filters;
- err = evlist__mmap(evlist, trace->opts.mmap_pages);
- if (err < 0)
- goto out_error_mmap;
+ if (!trace->summary_bpf) {
+ err = evlist__mmap(evlist, trace->opts.mmap_pages);
+ if (err < 0)
+ goto out_error_mmap;
+ }
if (!target__none(&trace->opts.target) && !trace->opts.target.initial_delay)
evlist__enable(evlist);
@@ -4441,6 +4453,9 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
evlist__enable(evlist);
}
+ if (trace->summary_bpf)
+ trace_start_bpf_summary();
+
trace->multiple_threads = perf_thread_map__pid(evlist->core.threads, 0) == -1 ||
perf_thread_map__nr(evlist->core.threads) > 1 ||
evlist__first(evlist)->core.attr.inherit;
@@ -4508,12 +4523,17 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
evlist__disable(evlist);
+ if (trace->summary_bpf)
+ trace_end_bpf_summary();
+
if (trace->sort_events)
ordered_events__flush(&trace->oe.data, OE_FLUSH__FINAL);
if (!err) {
if (trace->summary) {
- if (trace->summary_mode == SUMMARY__BY_TOTAL)
+ if (trace->summary_bpf)
+ trace_print_bpf_summary(trace->sctbl, trace->output);
+ else if (trace->summary_mode == SUMMARY__BY_TOTAL)
trace__fprintf_total_summary(trace, trace->output);
else
trace__fprintf_thread_summary(trace, trace->output);
@@ -4529,6 +4549,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
}
out_delete_evlist:
+ trace_cleanup_bpf_summary();
delete_syscall_stats(trace->syscall_stats);
trace__symbols__exit(trace);
evlist__free_syscall_tp_fields(evlist);
@@ -5446,6 +5467,15 @@ int cmd_trace(int argc, const char **argv)
goto skip_augmentation;
}
+ if (!argc && target__none(&trace.opts.target))
+ trace.opts.target.system_wide = true;
+
+ if (trace.summary_only && trace.opts.target.system_wide &&
+ trace.summary_mode == SUMMARY__BY_TOTAL && !trace.trace_pgfaults) {
+ trace.summary_bpf = true;
+ goto skip_augmentation;
+ }
+
trace.skel = augmented_raw_syscalls_bpf__open();
if (!trace.skel) {
pr_debug("Failed to open augmented syscalls BPF skeleton");
@@ -5649,9 +5679,6 @@ int cmd_trace(int argc, const char **argv)
goto out_close;
}
- if (!argc && target__none(&trace.opts.target))
- trace.opts.target.system_wide = true;
-
if (input_name)
err = trace__replay(&trace);
else
@@ -171,6 +171,7 @@ perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf_off_cpu.o
perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf-filter.o
perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf-filter-flex.o
perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf-filter-bison.o
+perf-util-$(CONFIG_PERF_BPF_SKEL) += bpf-trace-summary.o
perf-util-$(CONFIG_PERF_BPF_SKEL) += btf.o
ifeq ($(CONFIG_LIBTRACEEVENT),y)
new file mode 100644
@@ -0,0 +1,117 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "syscalltbl.h"
+#include "util/trace.h"
+#include "util/util.h"
+#include <bpf/bpf.h>
+#include <linux/time64.h>
+
+#include "bpf_skel/syscall_summary.h"
+#include "bpf_skel/syscall_summary.skel.h"
+
+
+static struct syscall_summary_bpf *skel;
+
+int trace_prepare_bpf_summary(void)
+{
+ skel = syscall_summary_bpf__open_and_load();
+ if (skel == NULL) {
+ fprintf(stderr, "failed to load syscall summary bpf skeleton\n");
+ return -1;
+ }
+
+ if (syscall_summary_bpf__attach(skel) < 0) {
+ fprintf(stderr, "failed to attach syscall summary bpf skeleton\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+void trace_start_bpf_summary(void)
+{
+ skel->bss->enabled = 1;
+}
+
+void trace_end_bpf_summary(void)
+{
+ skel->bss->enabled = 0;
+}
+
+struct syscall_data {
+ int syscall_nr;
+ struct syscall_stats stats;
+};
+
+static int datacmp(const void *a, const void *b)
+{
+ const struct syscall_data *sa = a;
+ const struct syscall_data *sb = b;
+
+ return sa->stats.total_time > sb->stats.total_time ? -1 : 1;
+}
+
+int trace_print_bpf_summary(struct syscalltbl *sctbl, FILE *fp)
+{
+ struct syscall_key *prev_key, key;
+ struct syscall_data *data = NULL;
+ struct bpf_map *map = skel->maps.syscall_stats_map;
+ int nr_data = 0;
+ int printed = 0;
+
+ /* get stats from the bpf map */
+ prev_key = NULL;
+ while (!bpf_map__get_next_key(map, prev_key, &key, sizeof(key))) {
+ struct syscall_stats stat;
+
+ if (!bpf_map__lookup_elem(map, &key, sizeof(key), &stat, sizeof(stat), 0)) {
+ struct syscall_data *tmp, *pos;
+
+ tmp = realloc(data, sizeof(*data) * (nr_data + 1));
+ if (tmp == NULL)
+ break;
+
+ data = tmp;
+ pos = &data[nr_data++];
+
+ pos->syscall_nr = key.nr;
+ memcpy(&pos->stats, &stat, sizeof(stat));
+ }
+
+ prev_key = &key;
+ }
+
+ qsort(data, nr_data, sizeof(*data), datacmp);
+
+ printed += fprintf(fp, "\n");
+
+ printed += fprintf(fp, " syscall calls errors total min avg max stddev\n");
+ printed += fprintf(fp, " (msec) (msec) (msec) (msec) (%%)\n");
+ printed += fprintf(fp, " --------------- -------- ------ -------- --------- --------- --------- ------\n");
+
+ for (int i = 0; i < nr_data; i++) {
+ struct syscall_data *pos = &data[i];
+ double total = (double)(pos->stats.total_time) / NSEC_PER_MSEC;
+ double min = (double)(pos->stats.min_time) / NSEC_PER_MSEC;
+ double max = (double)(pos->stats.max_time) / NSEC_PER_MSEC;
+ double avg = total / pos->stats.count;
+
+ printed += fprintf(fp, " %-15s", syscalltbl__name(sctbl, pos->syscall_nr));
+ printed += fprintf(fp, " %8u %6u %9.3f %9.3f %9.3f %9.3f %9.2f%%\n",
+ pos->stats.count, pos->stats.error, total, min, avg, max,
+ /*stddev=*/0.0);
+ }
+
+ printed += fprintf(fp, "\n\n");
+ free(data);
+
+ return printed;
+}
+
+void trace_cleanup_bpf_summary(void)
+{
+ syscall_summary_bpf__destroy(skel);
+}
new file mode 100644
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Trace raw_syscalls tracepoints to collect system call statistics.
+ */
+
+#include "vmlinux.h"
+#include "syscall_summary.h"
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+/* This is to calculate a delta between sys-enter and sys-exit for each thread */
+struct syscall_trace {
+ int nr; /* syscall number is only available at sys-enter */
+ int unused;
+ u64 timestamp;
+};
+
+#define MAX_ENTRIES (16 * 1024)
+
+struct syscall_trace_map {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, int); /* tid */
+ __type(value, struct syscall_trace);
+ __uint(max_entries, MAX_ENTRIES);
+} syscall_trace_map SEC(".maps");
+
+struct syscall_stats_map {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, struct syscall_key);
+ __type(value, struct syscall_stats);
+ __uint(max_entries, MAX_ENTRIES);
+} syscall_stats_map SEC(".maps");
+
+int enabled; /* controlled from userspace */
+
+static void update_stats(int nr, s64 duration, long ret)
+{
+ struct syscall_key key = { .nr = nr, };
+ struct syscall_stats *stats;
+
+ stats = bpf_map_lookup_elem(&syscall_stats_map, &key);
+ if (stats == NULL) {
+ struct syscall_stats zero = {};
+
+ bpf_map_update_elem(&syscall_stats_map, &key, &zero, BPF_NOEXIST);
+ stats = bpf_map_lookup_elem(&syscall_stats_map, &key);
+ if (stats == NULL)
+ return;
+ }
+
+ __sync_fetch_and_add(&stats->count, 1);
+ if (ret < 0)
+ __sync_fetch_and_add(&stats->error, 1);
+
+ if (duration > 0) {
+ __sync_fetch_and_add(&stats->total_time, duration);
+ if (stats->max_time < duration)
+ stats->max_time = duration;
+ if (stats->min_time > duration || stats->min_time == 0)
+ stats->min_time = duration;
+ }
+
+ return;
+}
+
+SEC("tp_btf/sys_enter")
+int sys_enter(u64 *ctx)
+{
+ int tid;
+ struct syscall_trace st;
+
+ if (!enabled)
+ return 0;
+
+ st.nr = ctx[1]; /* syscall number */
+ st.unused = 0;
+ st.timestamp = bpf_ktime_get_ns();
+
+ tid = bpf_get_current_pid_tgid();
+ bpf_map_update_elem(&syscall_trace_map, &tid, &st, BPF_ANY);
+
+ return 0;
+}
+
+SEC("tp_btf/sys_exit")
+int sys_exit(u64 *ctx)
+{
+ int tid;
+ long ret = ctx[1]; /* return value of the syscall */
+ struct syscall_trace *st;
+ s64 delta;
+
+ if (!enabled)
+ return 0;
+
+ tid = bpf_get_current_pid_tgid();
+ st = bpf_map_lookup_elem(&syscall_trace_map, &tid);
+ if (st == NULL)
+ return 0;
+
+ delta = bpf_ktime_get_ns() - st->timestamp;
+ update_stats(st->nr, delta, ret);
+
+ bpf_map_delete_elem(&syscall_trace_map, &tid);
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
new file mode 100644
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/* Data structures shared between BPF and tools. */
+#ifndef UTIL_BPF_SKEL_SYSCALL_SUMMARY_H
+#define UTIL_BPF_SKEL_SYSCALL_SUMMARY_H
+
+struct syscall_key {
+ int nr;
+};
+
+struct syscall_stats {
+ u64 total_time;
+ u64 max_time;
+ u64 min_time;
+ u32 count;
+ u32 error;
+};
+
+#endif /* UTIL_BPF_SKEL_SYSCALL_SUMMARY_H */
new file mode 100644
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef UTIL_TRACE_H
+#define UTIL_TRACE_H
+
+#include <stdio.h> /* for FILE */
+
+struct syscalltbl;
+
+#ifdef HAVE_BPF_SKEL
+
+int trace_prepare_bpf_summary(void);
+void trace_start_bpf_summary(void);
+void trace_end_bpf_summary(void);
+int trace_print_bpf_summary(struct syscalltbl *sctbl, FILE *fp);
+void trace_cleanup_bpf_summary(void);
+
+#else /* !HAVE_BPF_SKEL */
+
+static inline int trace_prepare_bpf_summary(void) { return -1; }
+static inline void trace_start_bpf_summary(void) {}
+static inline void trace_end_bpf_summary(void) {}
+static inline int trace_print_bpf_summary(struct syscalltbl *sctbl __maybe_unused,
+ FILE *fp __maybe_unused)
+{
+ return 0;
+}
+static inline void trace_cleanup_bpf_summary(void) {}
+
+#endif /* HAVE_BPF_SKEL */
+
+#endif /* UTIL_TRACE_H */
When --summary-only option is used, it doesn't need (augmented) arguments of syscalls. Let's skip the augmentation and load another small BPF program to collect the statistics in the kernel instead of copying the data to the ring-buffer to calculate the stats in userspace. This will be much more light-weight than the existing approach and remove any lost events. For simplicity, it's only activated with --summary-mode=total in system- wide mode. And it also skips to calculate stddev as doing it atomically would add more overheads (i.e. requiring a spinlock). It can be extended to cover more use cases later, if needed. Cc: Howard Chu <howardchu95@gmail.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- tools/perf/Makefile.perf | 2 +- tools/perf/builtin-trace.c | 41 ++++-- tools/perf/util/Build | 1 + tools/perf/util/bpf-trace-summary.c | 117 ++++++++++++++++++ .../perf/util/bpf_skel/syscall_summary.bpf.c | 109 ++++++++++++++++ tools/perf/util/bpf_skel/syscall_summary.h | 18 +++ tools/perf/util/trace.h | 31 +++++ 7 files changed, 311 insertions(+), 8 deletions(-) create mode 100644 tools/perf/util/bpf-trace-summary.c create mode 100644 tools/perf/util/bpf_skel/syscall_summary.bpf.c create mode 100644 tools/perf/util/bpf_skel/syscall_summary.h create mode 100644 tools/perf/util/trace.h