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From:   Shunsuke <nakamura.shun@fujitsu.com>
To:     peterz@infradead.org, mingo@redhat.com, acme@kernel.org,
        mark.rutland@arm.com, alexander.shishkin@linux.intel.com,
        jolsa@redhat.com, namhyung@kernel.org
Cc:     linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
        Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Subject: [RFC PATCH 7/7] libperf test: Add test_detect_overflow_event()
Date:   Fri, 25 Feb 2022 19:31:14 +0900
Message-Id: <20220225103114.144239-8-nakamura.shun@fujitsu.com>
In-Reply-To: <20220225103114.144239-1-nakamura.shun@fujitsu.com>
References: <20220225103114.144239-1-nakamura.shun@fujitsu.com>
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From: Shunsuke Nakamura <nakamura.shun@fujitsu.com>

Add a test to detect overflowed events.

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>

  Event  0 -- overflow flag = 0x1, POLL_UP = 1, other signal event = 0
  Event  1 -- overflow flag = 0x2, POLL_UP = 1, other signal event = 0
  Event  2 -- overflow flag = 0x4, POLL_UP = 1, other signal event = 0
  Event  3 -- overflow flag = 0x8, POLL_UP = 1, other signal event = 0
  OK
  - running tests/test-evsel.c...

  <SNIP>

  OK
  running dynamic:
  - running tests/test-cpumap.c...OK
  - running tests/test-threadmap.c...OK
  - running tests/test-evlist.c...

  <SNIP>

  Event  0 -- overflow flag = 0x1, POLL_UP = 1, other signal event = 0
  Event  1 -- overflow flag = 0x2, POLL_UP = 1, other signal event = 0
  Event  2 -- overflow flag = 0x4, POLL_UP = 1, other signal event = 0
  Event  3 -- overflow flag = 0x8, POLL_UP = 1, other signal event = 0
  OK
  - running tests/test-evsel.c...

  <SNIP>

  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>
---
 tools/lib/perf/tests/test-evlist.c | 119 +++++++++++++++++++++++++++++
 1 file changed, 119 insertions(+)

diff --git a/tools/lib/perf/tests/test-evlist.c b/tools/lib/perf/tests/test-evlist.c
index fafc6b0f8687..c0f0109c8b51 100644
--- a/tools/lib/perf/tests/test-evlist.c
+++ b/tools/lib/perf/tests/test-evlist.c
@@ -5,6 +5,8 @@
 #include <stdarg.h>
 #include <unistd.h>
 #include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
 #include <linux/perf_event.h>
 #include <linux/limits.h>
 #include <sys/types.h>
@@ -24,6 +26,13 @@
 #define EVENT_NUM 15
 #define WAIT_COUNT 100000000UL
 
+static unsigned int overflow_flag;
+static struct signal_counts {
+	int hup;
+	int others;
+} sig_count = { 0, 0 };
+static struct perf_evlist *s_evlist;
+
 static int libperf_print(enum libperf_print_level level,
 			 const char *fmt, va_list ap)
 {
@@ -570,6 +579,115 @@ static int test_stat_multiplexing(void)
 	return 0;
 }
 
+static void sig_handler(int signo, siginfo_t *info, void *uc)
+{
+	int err;
+	int idx = 0;
+	struct perf_evsel *evsel;
+
+	switch (info->si_code) {
+	case POLL_HUP:
+		perf_evlist__for_each_evsel(s_evlist, evsel) {
+			err = perf_evsel__check_fd(evsel, info->si_fd);
+			if (!err) {
+				overflow_flag = (1U << idx);
+				sig_count.hup++;
+				break;
+			}
+			idx++;
+		}
+		break;
+	default:
+		perf_evlist__for_each_evsel(s_evlist, evsel) {
+			err = perf_evsel__check_fd(evsel, info->si_fd);
+			if (!err) {
+				overflow_flag = (1U << idx);
+				sig_count.others++;
+				break;
+			}
+			idx++;
+		}
+	}
+}
+
+static int test_stat_overflow_event(void)
+{
+	static struct sigaction sig;
+
+	struct perf_thread_map *threads;
+	struct perf_evsel *evsel;
+	struct perf_event_attr attr = {
+		.type		= PERF_TYPE_SOFTWARE,
+		.config		= PERF_COUNT_SW_CPU_CLOCK,
+		.sample_type    = PERF_SAMPLE_PERIOD,
+		.sample_period  = 100000,
+		.disabled       = 1,
+	};
+	int err, i, event_num = 4;
+	unsigned int wait_count;
+
+	/* 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_evlist = perf_evlist__new();
+	__T("failed to create evlist", s_evlist);
+
+	for (i = 0; i < event_num; i++) {
+		evsel = perf_evsel__new(&attr);
+		__T("failed to create evsel", evsel);
+
+		err = perf_evsel__set_close_on_exec(evsel);
+		__T("failed to set PERF_FLAG_FD_CLOEXEC flag to evsel", err == 0);
+
+		perf_evlist__add(s_evlist, evsel);
+	}
+
+	perf_evlist__set_maps(s_evlist, NULL, threads);
+
+	err = perf_evlist__open(s_evlist);
+	__T("failed to open evlist", err == 0);
+
+	i = 0;
+	perf_evlist__for_each_evsel(s_evlist, evsel) {
+		err = perf_evsel__set_signal(evsel, F_OWNER_PID, SIGIO, &sig);
+		__T("failed to set signal", err == 0);
+
+		err = perf_evsel__refresh(evsel, 1);
+		__T("failed to refresh evsel", err == 0);
+
+		wait_count = WAIT_COUNT;
+		while (wait_count--)
+			;
+
+		__T_VERBOSE("Event %2d -- overflow flag = %#x, ",
+			    i, overflow_flag);
+		__T_VERBOSE("POLL_UP = %d, other signal event = %d\n",
+			    sig_count.hup, sig_count.others);
+
+		__T("unexpected event overflow detected", overflow_flag && (1U << i));
+		__T("unexpected signal event detected",
+		    sig_count.hup == 1 && sig_count.others == 0);
+
+		overflow_flag = 0;
+		sig_count.hup = 0;
+		sig_count.others = 0;
+		i++;
+	}
+
+	perf_evlist__close(s_evlist);
+	perf_evlist__delete(s_evlist);
+	perf_thread_map__put(threads);
+
+	return 0;
+}
+
 int test_evlist(int argc, char **argv)
 {
 	__T_START;
@@ -582,6 +700,7 @@ int test_evlist(int argc, char **argv)
 	test_mmap_thread();
 	test_mmap_cpus();
 	test_stat_multiplexing();
+	test_stat_overflow_event();
 
 	__T_END;
 	return tests_failed == 0 ? 0 : -1;
-- 
2.31.1