selftests/timers: Add mqueue latency test from the timetest suite

Add test to validate mqueue timeout latency from the timetest suite

Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

2 files changed, 126 insertions, 1 deletions

diff --git a/tools/testing/selftests/timers/Makefile b/tools/testing/selftests/timers/Makefile
index e53b675e3246..d0bfb2d007cf 100644
--- a/tools/testing/selftests/timers/Makefile
+++ b/tools/testing/selftests/timers/Makefile
@@ -3,7 +3,7 @@ BUILD_FLAGS = -DKTEST
 CFLAGS += -O3 -Wl,-no-as-needed -Wall $(BUILD_FLAGS)
 LDFLAGS += -lrt -lpthread
 bins = posix_timers nanosleep inconsistency-check nsleep-lat raw_skew \
-        set-timer-lat threadtest
+        set-timer-lat threadtest mqueue-lat
 
 all: ${bins}
 
@@ -12,6 +12,7 @@ run_tests: all
         ./nanosleep
         ./nsleep-lat
         ./set-timer-lat
+        ./mqueue-lat
         ./inconsistency-check
         ./raw_skew
         ./threadtest -t 30 -n 8
diff --git a/tools/testing/selftests/timers/mqueue-lat.c b/tools/testing/selftests/timers/mqueue-lat.c
new file mode 100644
index 000000000000..a2a3924d0b41
--- /dev/null
+++ b/tools/testing/selftests/timers/mqueue-lat.c
@@ -0,0 +1,124 @@
+/* Measure mqueue timeout latency
+ *              by: john stultz (john.stultz@linaro.org)
+ *              (C) Copyright Linaro 2013
+ *
+ *              Inspired with permission from example test by:
+ *                      Romain Francoise <romain@orebokech.com>
+ *              Licensed under the GPLv2
+ *
+ *  To build:
+ *      $ gcc mqueue-lat.c -o mqueue-lat -lrt
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <sys/time.h>
+#include <sys/timex.h>
+#include <string.h>
+#include <signal.h>
+#include <errno.h>
+#include <mqueue.h>
+#ifdef KTEST
+#include "../kselftest.h"
+#else
+static inline int ksft_exit_pass(void)
+{
+        exit(0);
+}
+static inline int ksft_exit_fail(void)
+{
+        exit(1);
+}
+#endif
+
+#define NSEC_PER_SEC 1000000000ULL
+
+#define TARGET_TIMEOUT          100000000       /* 100ms in nanoseconds */
+#define UNRESONABLE_LATENCY     40000000        /* 40ms in nanosecs */
+
+
+long long timespec_sub(struct timespec a, struct timespec b)
+{
+        long long ret = NSEC_PER_SEC * b.tv_sec + b.tv_nsec;
+
+        ret -= NSEC_PER_SEC * a.tv_sec + a.tv_nsec;
+        return ret;
+}
+
+struct timespec timespec_add(struct timespec ts, unsigned long long ns)
+{
+        ts.tv_nsec += ns;
+        while (ts.tv_nsec >= NSEC_PER_SEC) {
+                ts.tv_nsec -= NSEC_PER_SEC;
+                ts.tv_sec++;
+        }
+        return ts;
+}
+
+int mqueue_lat_test(void)
+{
+
+        mqd_t q;
+        struct mq_attr attr;
+        struct timespec start, end, now, target;
+        int i, count, ret;
+
+        q = mq_open("/foo", O_CREAT | O_RDONLY, 0666, NULL);
+        if (q < 0) {
+                perror("mq_open");
+                return -1;
+        }
+        mq_getattr(q, &attr);
+
+
+        count = 100;
+        clock_gettime(CLOCK_MONOTONIC, &start);
+
+        for (i = 0; i < count; i++) {
+                char buf[attr.mq_msgsize];
+
+                clock_gettime(CLOCK_REALTIME, &now);
+                target = now;
+                target = timespec_add(now, TARGET_TIMEOUT); /* 100ms */
+
+                ret = mq_timedreceive(q, buf, sizeof(buf), NULL, &target);
+                if (ret < 0 && errno != ETIMEDOUT) {
+                        perror("mq_timedreceive");
+                        return -1;
+                }
+        }
+        clock_gettime(CLOCK_MONOTONIC, &end);
+
+        mq_close(q);
+
+        if ((timespec_sub(start, end)/count) > TARGET_TIMEOUT + UNRESONABLE_LATENCY)
+                return -1;
+
+        return 0;
+}
+
+int main(int argc, char **argv)
+{
+        int ret;
+
+        printf("Mqueue latency :                          ");
+
+        ret = mqueue_lat_test();
+        if (ret < 0) {
+                printf("[FAILED]\n");
+                return ksft_exit_fail();
+        }
+        printf("[OK]\n");
+        return ksft_exit_pass();
+}