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

[Charlie Jenkins <charlie@rivosinc.com>]

From: Shunsuke Nakamura <nakamura.shun@fujitsu.com>

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