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Subject[PATCH 1/6] perf bench: Add build-id injection benchmark
Date
Sometimes I can see perf record piped with perf inject take long time
processing build-id. So add inject-build-id benchmark to the
internals benchmark suite to measure its overhead regularly.

It runs perf inject command internally and feeds the given number of
synthesized events (MMAP2 + SAMPLE basically).

Usage: perf bench internals inject-build-id <options>

-i, --iterations <n> Number of iterations used to compute average (default: 100)
-m, --nr-mmaps <n> Number of mmap events for each iteration (default: 100)
-n, --nr-samples <n> Number of sample events per mmap event (default: 100)
-v, --verbose be more verbose (show iteration count, DSO name, etc)

By default, it measures average processing time of 100 MMAP2 events
and 10000 SAMPLE events. Below is a result on my laptop.

$ perf bench internals inject-build-id
# Running 'internals/inject-build-id' benchmark:
Average build-id injection took: 23.885 msec (+- 0.114 msec)
Average time per event: 2.342 usec (+- 0.011 usec)
Average memory usage: 7864 KB (+- 10 KB)

Acked-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/bench/Build | 1 +
tools/perf/bench/bench.h | 1 +
tools/perf/bench/inject-buildid.c | 441 ++++++++++++++++++++++++++++++
tools/perf/builtin-bench.c | 1 +
tools/perf/builtin-inject.c | 9 +-
tools/perf/util/build-id.h | 4 +
6 files changed, 452 insertions(+), 5 deletions(-)
create mode 100644 tools/perf/bench/inject-buildid.c

diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index dd68a40a790c..8b52591338d6 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -12,6 +12,7 @@ perf-y += epoll-ctl.o
perf-y += synthesize.o
perf-y += kallsyms-parse.o
perf-y += find-bit-bench.o
+perf-y += inject-buildid.o

perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index 2804812d4154..eac36afab2b3 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -47,6 +47,7 @@ int bench_epoll_wait(int argc, const char **argv);
int bench_epoll_ctl(int argc, const char **argv);
int bench_synthesize(int argc, const char **argv);
int bench_kallsyms_parse(int argc, const char **argv);
+int bench_inject_build_id(int argc, const char **argv);

#define BENCH_FORMAT_DEFAULT_STR "default"
#define BENCH_FORMAT_DEFAULT 0
diff --git a/tools/perf/bench/inject-buildid.c b/tools/perf/bench/inject-buildid.c
new file mode 100644
index 000000000000..b09f9126bb4f
--- /dev/null
+++ b/tools/perf/bench/inject-buildid.c
@@ -0,0 +1,441 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdlib.h>
+#include <stddef.h>
+#include <ftw.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/wait.h>
+#include <linux/kernel.h>
+#include <linux/time64.h>
+#include <linux/list.h>
+#include <linux/err.h>
+#include <internal/lib.h>
+#include <subcmd/parse-options.h>
+
+#include "bench.h"
+#include "util/data.h"
+#include "util/stat.h"
+#include "util/debug.h"
+#include "util/event.h"
+#include "util/symbol.h"
+#include "util/session.h"
+#include "util/build-id.h"
+#include "util/synthetic-events.h"
+
+#define MMAP_DEV_MAJOR 8
+
+static unsigned int iterations = 100;
+static unsigned int nr_mmaps = 100;
+static unsigned int nr_samples = 100; /* samples per mmap */
+
+static u64 bench_sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
+static u16 bench_id_hdr_size = 8; /* only for pid/tid */
+
+struct bench_data {
+ int pid;
+ int input_pipe[2];
+ int output_pipe[2];
+};
+
+struct bench_dso {
+ struct list_head list;
+ char *name;
+ int ino;
+};
+
+static int nr_dsos;
+static LIST_HEAD(dso_list);
+
+extern int cmd_inject(int argc, const char *argv[]);
+
+static const struct option options[] = {
+ OPT_UINTEGER('i', "iterations", &iterations,
+ "Number of iterations used to compute average (default: 100)"),
+ OPT_UINTEGER('m', "nr-mmaps", &nr_mmaps,
+ "Number of mmap events for each iteration (default: 100)"),
+ OPT_UINTEGER('n', "nr-samples", &nr_samples,
+ "Number of sample events per mmap event (default: 100)"),
+ OPT_INCR('v', "verbose", &verbose,
+ "be more verbose (show iteration count, DSO name, etc)"),
+ OPT_END()
+};
+
+static const char *const bench_usage[] = {
+ "perf bench internals inject-build-id <options>",
+ NULL
+};
+
+/*
+ * Helper for collect_dso that adds the given file as a dso to dso_list
+ * if it contains a build-id. Stops after collecting 4 times more than
+ * we need (for MMAP2 events).
+ */
+static int add_dso(const char *fpath, const struct stat *sb __maybe_unused,
+ int typeflag, struct FTW *ftwbuf __maybe_unused)
+{
+ struct bench_dso *dso;
+ unsigned char build_id[BUILD_ID_SIZE];
+
+ if (typeflag == FTW_D || typeflag == FTW_SL)
+ return 0;
+
+ if (filename__read_build_id(fpath, build_id, BUILD_ID_SIZE) < 0)
+ return 0;
+
+ dso = malloc(sizeof(*dso));
+ if (dso == NULL)
+ return -1;
+
+ dso->name = realpath(fpath, NULL);
+ if (dso->name == NULL) {
+ free(dso);
+ return -1;
+ }
+
+ dso->ino = nr_dsos++;
+ list_add(&dso->list, &dso_list);
+ pr_debug2(" Adding DSO: %s\n", fpath);
+
+ /* stop if we collected 4x DSOs than needed */
+ if ((unsigned int)nr_dsos >= 4 * nr_mmaps)
+ return 1;
+
+ return 0;
+}
+
+static void collect_dso(void)
+{
+ if (nftw("/usr/lib/", add_dso, 10, FTW_PHYS) < 0)
+ return;
+
+ pr_debug(" Collected %d DSOs\n", nr_dsos);
+}
+
+static void release_dso(void)
+{
+ struct bench_dso *dso;
+
+ while (!list_empty(&dso_list)) {
+ dso = list_first_entry(&dso_list, struct bench_dso, list);
+ list_del(&dso->list);
+ free(dso->name);
+ free(dso);
+ }
+}
+
+/* Fake address used by mmap and sample events */
+static u64 dso_map_addr(struct bench_dso *dso)
+{
+ return 0x400000ULL + dso->ino * 8192ULL;
+}
+
+static u32 synthesize_attr(struct bench_data *data)
+{
+ union perf_event event;
+
+ memset(&event, 0, sizeof(event.attr) + sizeof(u64));
+
+ event.header.type = PERF_RECORD_HEADER_ATTR;
+ event.header.size = sizeof(event.attr) + sizeof(u64);
+
+ event.attr.attr.type = PERF_TYPE_SOFTWARE;
+ event.attr.attr.config = PERF_COUNT_SW_TASK_CLOCK;
+ event.attr.attr.exclude_kernel = 1;
+ event.attr.attr.sample_id_all = 1;
+ event.attr.attr.sample_type = bench_sample_type;
+
+ return writen(data->input_pipe[1], &event, event.header.size);
+}
+
+static u32 synthesize_fork(struct bench_data *data)
+{
+ union perf_event event;
+
+ memset(&event, 0, sizeof(event.fork) + bench_id_hdr_size);
+
+ event.header.type = PERF_RECORD_FORK;
+ event.header.misc = PERF_RECORD_MISC_FORK_EXEC;
+ event.header.size = sizeof(event.fork) + bench_id_hdr_size;
+
+ event.fork.ppid = 1;
+ event.fork.ptid = 1;
+ event.fork.pid = data->pid;
+ event.fork.tid = data->pid;
+
+ return writen(data->input_pipe[1], &event, event.header.size);
+}
+
+static u32 synthesize_mmap(struct bench_data *data, struct bench_dso *dso)
+{
+ union perf_event event;
+ size_t len = offsetof(struct perf_record_mmap2, filename);
+
+ len += roundup(strlen(dso->name) + 1, 8) + bench_id_hdr_size;
+
+ memset(&event, 0, min(len, sizeof(event.mmap2)));
+
+ event.header.type = PERF_RECORD_MMAP2;
+ event.header.misc = PERF_RECORD_MISC_USER;
+ event.header.size = len;
+
+ event.mmap2.pid = data->pid;
+ event.mmap2.tid = data->pid;
+ event.mmap2.maj = MMAP_DEV_MAJOR;
+ event.mmap2.ino = dso->ino;
+
+ strcpy(event.mmap2.filename, dso->name);
+
+ event.mmap2.start = dso_map_addr(dso);
+ event.mmap2.len = 4096;
+ event.mmap2.prot = PROT_EXEC;
+
+ if (len > sizeof(event.mmap2)) {
+ /* write mmap2 event first */
+ writen(data->input_pipe[1], &event, len - bench_id_hdr_size);
+ /* write zero-filled sample id header */
+ memset(&event, 0, bench_id_hdr_size);
+ writen(data->input_pipe[1], &event, bench_id_hdr_size);
+ } else {
+ writen(data->input_pipe[1], &event, len);
+ }
+ return len;
+}
+
+static u32 synthesize_sample(struct bench_data *data, struct bench_dso *dso)
+{
+ union perf_event event;
+ struct perf_sample sample = {
+ .tid = data->pid,
+ .pid = data->pid,
+ .ip = dso_map_addr(dso),
+ };
+
+ event.header.type = PERF_RECORD_SAMPLE;
+ event.header.misc = PERF_RECORD_MISC_USER;
+ event.header.size = perf_event__sample_event_size(&sample, bench_sample_type, 0);
+
+ perf_event__synthesize_sample(&event, bench_sample_type, 0, &sample);
+
+ return writen(data->input_pipe[1], &event, event.header.size);
+}
+
+static void sigpipe_handler(int sig __maybe_unused)
+{
+ /* child exited */
+}
+
+static int setup_injection(struct bench_data *data)
+{
+ int ready_pipe[2];
+ int dev_null_fd;
+ char buf;
+
+ if (pipe(ready_pipe) < 0)
+ return -1;
+
+ if (pipe(data->input_pipe) < 0)
+ return -1;
+
+ if (pipe(data->output_pipe) < 0)
+ return -1;
+
+ data->pid = fork();
+ if (data->pid < 0)
+ return -1;
+
+ if (data->pid == 0) {
+ const char **inject_argv;
+
+ close(data->input_pipe[1]);
+ close(data->output_pipe[0]);
+ close(ready_pipe[0]);
+
+ dup2(data->input_pipe[0], STDIN_FILENO);
+ close(data->input_pipe[0]);
+ dup2(data->output_pipe[1], STDOUT_FILENO);
+ close(data->output_pipe[1]);
+
+ dev_null_fd = open("/dev/null", O_WRONLY);
+ if (dev_null_fd < 0)
+ exit(1);
+
+ dup2(dev_null_fd, STDERR_FILENO);
+
+ inject_argv = calloc(3, sizeof(*inject_argv));
+ if (inject_argv == NULL)
+ exit(1);
+
+ inject_argv[0] = strdup("inject");
+ inject_argv[1] = strdup("-b");
+
+ /* signal that we're ready to go */
+ close(ready_pipe[1]);
+
+ cmd_inject(2, inject_argv);
+
+ exit(0);
+ }
+
+ signal(SIGPIPE, sigpipe_handler);
+
+ close(ready_pipe[1]);
+ close(data->input_pipe[0]);
+ close(data->output_pipe[1]);
+
+ /* wait for child ready */
+ if (read(ready_pipe[0], &buf, 1) < 0)
+ return -1;
+ close(ready_pipe[0]);
+
+ return 0;
+}
+
+static int inject_build_id(struct bench_data *data, u64 *max_rss)
+{
+ int flag, status;
+ unsigned int i, k;
+ char buf[8192];
+ u64 nread = 0;
+ u64 len = nr_mmaps * sizeof(struct perf_record_header_build_id);
+ struct rusage rusage;
+
+ flag = fcntl(data->output_pipe[0], F_GETFL, 0);
+ if (fcntl(data->output_pipe[0], F_SETFL, flag | O_NONBLOCK) < 0)
+ return -1;
+
+ /* this makes the child to run */
+ if (perf_header__write_pipe(data->input_pipe[1]) < 0)
+ return -1;
+
+ len += synthesize_attr(data);
+ len += synthesize_fork(data);
+
+ for (i = 0; i < nr_mmaps; i++) {
+ struct bench_dso *dso;
+ int idx = rand() % (nr_dsos - 1);
+
+ dso = list_first_entry(&dso_list, struct bench_dso, list);
+ while (idx--)
+ dso = list_next_entry(dso, list);
+
+ pr_debug2(" [%d] injecting: %s\n", i+1, dso->name);
+ len += synthesize_mmap(data, dso);
+
+ for (k = 0; k < nr_samples; k++)
+ len += synthesize_sample(data, dso);
+
+ /* read out data from child */
+ while (true) {
+ int n;
+
+ n = read(data->output_pipe[0], buf, sizeof(buf));
+ if (n <= 0)
+ break;
+ nread += n;
+ }
+ }
+
+ /* wait to read data at least as we wrote + build-ids */
+ while (nread < len) {
+ int n;
+
+ n = read(data->output_pipe[0], buf, sizeof(buf));
+ if (n < 0) {
+ if (errno == EINTR || errno == EAGAIN) {
+ usleep(100);
+ continue;
+ }
+ break;
+ }
+ nread += n;
+ }
+ close(data->input_pipe[1]);
+ close(data->output_pipe[0]);
+
+ pr_debug(" read %lu / %lu bytes\n", nread, len);
+
+ wait4(data->pid, &status, 0, &rusage);
+ *max_rss = rusage.ru_maxrss;
+
+ pr_debug(" Child %d exited with %d\n", data->pid, status);
+
+ return 0;
+}
+
+static int do_inject_loop(struct bench_data *data)
+{
+ unsigned int i;
+ struct stats time_stats, mem_stats;
+ double time_average, time_stddev;
+ double mem_average, mem_stddev;
+
+ srand(time(NULL));
+ init_stats(&time_stats);
+ init_stats(&mem_stats);
+ symbol__init(NULL);
+
+ collect_dso();
+ if (nr_dsos == 0) {
+ printf(" Cannot collect DSOs for injection\n");
+ return -1;
+ }
+
+ for (i = 0; i < iterations; i++) {
+ struct timeval start, end, diff;
+ u64 runtime_us, max_rss;
+
+ pr_debug(" Iteration #%d\n", i+1);
+
+ if (setup_injection(data) < 0) {
+ printf(" Build-id injection setup failed\n");
+ break;
+ }
+
+ gettimeofday(&start, NULL);
+ if (inject_build_id(data, &max_rss) < 0) {
+ printf(" Build-id injection failed\n");
+ break;
+ }
+
+ gettimeofday(&end, NULL);
+ timersub(&end, &start, &diff);
+ runtime_us = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
+ update_stats(&time_stats, runtime_us);
+ update_stats(&mem_stats, max_rss);
+ }
+
+ time_average = avg_stats(&time_stats) / USEC_PER_MSEC;
+ time_stddev = stddev_stats(&time_stats) / USEC_PER_MSEC;
+ printf(" Average build-id injection took: %.3f msec (+- %.3f msec)\n",
+ time_average, time_stddev);
+
+ /* each iteration, it processes MMAP2 + BUILD_ID + nr_samples * SAMPLE */
+ time_average = avg_stats(&time_stats) / (nr_mmaps * (nr_samples + 2));
+ time_stddev = stddev_stats(&time_stats) / (nr_mmaps * (nr_samples + 2));
+ printf(" Average time per event: %.3f usec (+- %.3f usec)\n",
+ time_average, time_stddev);
+
+ mem_average = avg_stats(&mem_stats);
+ mem_stddev = stddev_stats(&mem_stats);
+ printf(" Average memory usage: %.0f KB (+- %.0f KB)\n",
+ mem_average, mem_stddev);
+
+ release_dso();
+ return 0;
+}
+
+int bench_inject_build_id(int argc, const char **argv)
+{
+ struct bench_data data;
+
+ argc = parse_options(argc, argv, options, bench_usage, 0);
+ if (argc) {
+ usage_with_options(bench_usage, options);
+ exit(EXIT_FAILURE);
+ }
+
+ return do_inject_loop(&data);
+}
+
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index 4f176039fc8f..62a7b7420a44 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c
@@ -87,6 +87,7 @@ static struct bench epoll_benchmarks[] = {
static struct bench internals_benchmarks[] = {
{ "synthesize", "Benchmark perf event synthesis", bench_synthesize },
{ "kallsyms-parse", "Benchmark kallsyms parsing", bench_kallsyms_parse },
+ { "inject-build-id", "Benchmark build-id injection", bench_inject_build_id },
{ NULL, NULL, NULL }
};

diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 6d2f410d773a..e4d78f11494e 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -441,11 +441,10 @@ static int dso__inject_build_id(struct dso *dso, struct perf_tool *tool,
return 0;
}

-static int perf_event__inject_buildid(struct perf_tool *tool,
- union perf_event *event,
- struct perf_sample *sample,
- struct evsel *evsel __maybe_unused,
- struct machine *machine)
+int perf_event__inject_buildid(struct perf_tool *tool, union perf_event *event,
+ struct perf_sample *sample,
+ struct evsel *evsel __maybe_unused,
+ struct machine *machine)
{
struct addr_location al;
struct thread *thread;
diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
index aad419bb165c..949f7e54c9cb 100644
--- a/tools/perf/util/build-id.h
+++ b/tools/perf/util/build-id.h
@@ -29,6 +29,10 @@ int build_id__mark_dso_hit(struct perf_tool *tool, union perf_event *event,

int dsos__hit_all(struct perf_session *session);

+int perf_event__inject_buildid(struct perf_tool *tool, union perf_event *event,
+ struct perf_sample *sample, struct evsel *evsel,
+ struct machine *machine);
+
bool perf_session__read_build_ids(struct perf_session *session, bool with_hits);
int perf_session__write_buildid_table(struct perf_session *session,
struct feat_fd *fd);
--
2.28.0.681.g6f77f65b4e-goog
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