[PATCH v2 7/8] libperf test: Add test_stat_overflow()

Charlie Jenkins
2024-07-29T16:46:18Z

Added overflow test using refresh and period.

Confirmation
- That the overflow occurs the number of times specified by
perf_evse__refresh()
- That the period can be updated by perf_evsel__period()

Committer testing:

$ sudo make tests -C ./tools/lib/perf V=1
make: Entering directory '/home/nakamura/build_work/build_kernel/linux-kernel/linux/tools/lib/perf'
make -f /home/nakamura/build_work/build_kernel/linux-kernel/linux/tools/build/Makefile.build dir=. obj=libperf
make -C /home/nakamura/build_work/build_kernel/linux-kernel/linux/tools/lib/api/ O= libapi.a
make -f /home/nakamura/build_work/build_kernel/linux-kernel/linux/tools/build/Makefile.build dir=./fd obj=libapi
make -f /home/nakamura/build_work/build_kernel/linux-kernel/linux/tools/build/Makefile.build dir=./fs obj=libapi
make -f /home/nakamura/build_work/build_kernel/linux-kernel/linux/tools/build/Makefile.build dir=. obj=tests
make -f /home/nakamura/build_work/build_kernel/linux-kernel/linux/tools/build/Makefile.build dir=./tests obj=tests
running static:
- running tests/test-cpumap.c...OK
- running tests/test-threadmap.c...OK
- running tests/test-evlist.c...

<SNIP>

OK
- running tests/test-evsel.c...

<SNIP>

period = 1000000
overflow limit = 3, overflow count = 3, POLL_IN = 2, POLL_HUP = 1, other signal event = 0
period = 2000000
overflow limit = 3, overflow count = 3, POLL_IN = 2, POLL_HUP = 1, other signal event = 0
period = 1000000
overflow limit = 3, overflow count = 3, POLL_IN = 2, POLL_HUP = 1, other signal event = 0
period = 2000000
overflow limit = 3, overflow count = 3, POLL_IN = 2, POLL_HUP = 1, other signal event = 0
OK
running dynamic:
- running tests/test-cpumap.c...OK
- running tests/test-threadmap.c...OK
- running tests/test-evlist.c...

<SNIP>

OK
- running tests/test-evsel.c...

<SNIP>

period = 1000000
overflow limit = 3, overflow count = 3, POLL_IN = 2, POLL_HUP = 1, other signal event = 0
period = 2000000
overflow limit = 3, overflow count = 3, POLL_IN = 2, POLL_HUP = 1, other signal event = 0
period = 1000000
overflow limit = 3, overflow count = 3, POLL_IN = 2, POLL_HUP = 1, other signal event = 0
period = 2000000
overflow limit = 3, overflow count = 3, POLL_IN = 2, POLL_HUP = 1, other signal event = 0
OK
make: Leaving directory '/home/nakamura/build_work/build_kernel/linux-kernel/linux/tools/lib/perf'

Signed-off-by: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
---
tools/lib/perf/tests/test-evsel.c | 107 ++++++++++++++++++++++++++++++++++++++
1 file changed, 107 insertions(+)

diff --git a/tools/lib/perf/tests/test-evsel.c b/tools/lib/perf/tests/test-evsel.c
index 545ec3150546..b27dd65f2ec9 100644
--- a/tools/lib/perf/tests/test-evsel.c
+++ b/tools/lib/perf/tests/test-evsel.c
@@ -1,7 +1,11 @@
// SPDX-License-Identifier: GPL-2.0
+#include <inttypes.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
+#include <signal.h>
+#include <unistd.h>
+#include <fcntl.h>
#include <linux/perf_event.h>
#include <linux/kernel.h>
#include <perf/cpumap.h>
@@ -11,6 +15,15 @@
#include <internal/tests.h>
#include "tests.h"

+#define WAIT_COUNT 10000000UL
+static struct signal_counts {
+ int in;
+ int hup;
+ int others;
+ int overflow;
+} sig_count;
+static struct perf_evsel *s_evsel;
+
static int libperf_print(enum libperf_print_level level,
const char *fmt, va_list ap)
{
@@ -349,6 +362,98 @@ static int test_stat_read_format(void)
return 0;
}

+static void sig_handler(int signo, siginfo_t *info, void *uc)
+{
+ switch (info->si_code) {
+ case POLL_IN:
+ sig_count.in++;
+ break;
+ case POLL_HUP:
+ sig_count.hup++;
+ break;
+ default:
+ sig_count.others++;
+ }
+
+ sig_count.overflow++;
+}
+
+static int test_stat_overflow(int owner)
+{
+ static struct sigaction sig;
+ u64 period = 1000000;
+ int overflow_limit = 3;
+
+ struct perf_thread_map *threads;
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_SOFTWARE,
+ .config = PERF_COUNT_SW_TASK_CLOCK,
+ .sample_type = PERF_SAMPLE_PERIOD,
+ .sample_period = period,
+ .disabled = 1,
+ };
+ struct perf_event_attr *tmp_attr;
+ int err = 0, i;
+
+ LIBPERF_OPTS(perf_evsel_open_opts, opts,
+ .open_flags = PERF_FLAG_FD_CLOEXEC,
+ .flags = (O_RDWR | O_NONBLOCK | O_ASYNC),
+ .signal = SIGRTMIN + 1,
+ .owner_type = owner,
+ .sig = &sig);
+
+ /* setup signal handler */
+ memset(&sig, 0, sizeof(struct sigaction));
+ sig.sa_sigaction = (void *)sig_handler;
+ sig.sa_flags = SA_SIGINFO;
+
+ threads = perf_thread_map__new_dummy();
+ __T("failed to create threads", threads);
+
+ perf_thread_map__set_pid(threads, 0, 0);
+
+ s_evsel = perf_evsel__new(&attr);
+ __T("failed to create evsel", s_evsel);
+
+ err = perf_evsel__open_opts(s_evsel, NULL, threads, &opts);
+ __T("failed to open evsel", err == 0);
+
+ for (i = 0; i < 2; i++) {
+ volatile unsigned int wait_count = WAIT_COUNT;
+
+ sig_count.in = 0;
+ sig_count.hup = 0;
+ sig_count.others = 0;
+ sig_count.overflow = 0;
+
+ period = period << i;
+ err = perf_evsel__period(s_evsel, period);
+ __T("failed to period evsel", err == 0);
+
+ tmp_attr = perf_evsel__attr(s_evsel);
+ __T_VERBOSE("\tperiod = %llu\n", tmp_attr->sample_period);
+
+ err = perf_evsel__refresh(s_evsel, overflow_limit);
+ __T("failed to refresh evsel", err == 0);
+
+ while (wait_count--)
+ ;
+
+ __T_VERBOSE("\toverflow limit = %d, overflow count = %d, ",
+ overflow_limit, sig_count.overflow);
+ __T_VERBOSE("POLL_IN = %d, POLL_HUP = %d, other signal event = %d\n",
+ sig_count.in, sig_count.hup, sig_count.others);
+
+ __T("failed to overflow count", overflow_limit == sig_count.overflow);
+ }
+
+ perf_evsel__close(s_evsel);
+ perf_evsel__delete(s_evsel);
+ perf_thread_map__put(threads);
+
+ return 0;
+}
+
int test_evsel(int argc, char **argv)
{
__T_START;
@@ -361,6 +466,8 @@ int test_evsel(int argc, char **argv)
test_stat_user_read(PERF_COUNT_HW_INSTRUCTIONS);
test_stat_user_read(PERF_COUNT_HW_CPU_CYCLES);
test_stat_read_format();
+ test_stat_overflow(F_OWNER_PID);
+ test_stat_overflow(F_OWNER_TID);

__T_END;
return tests_failed == 0 ? 0 : -1;

--
2.44.0