bc7e5d23be
After commit f7d5bcd35d ("selftests: kselftest: Mark functions that
unconditionally call exit() as __noreturn"), ksft_exit_...() functions
are marked as __noreturn, which means the return type should not be
'int' but 'void' because they are not returning anything (and never were
since exit() has always been called).
To facilitate updating the return type of these functions, remove
'return' before the calls to ksft_exit_...(), as __noreturn prevents the
compiler from warning that a caller of the ksft_exit functions does not
return a value because the program will terminate upon calling these
functions.
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
114 lines
2.6 KiB
C
114 lines
2.6 KiB
C
/* Measure mqueue timeout latency
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* by: john stultz (john.stultz@linaro.org)
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* (C) Copyright Linaro 2013
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*
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* Inspired with permission from example test by:
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* Romain Francoise <romain@orebokech.com>
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* Licensed under the GPLv2
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*
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* To build:
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* $ gcc mqueue-lat.c -o mqueue-lat -lrt
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <time.h>
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#include <sys/time.h>
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#include <sys/timex.h>
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#include <string.h>
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#include <signal.h>
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#include <errno.h>
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#include <mqueue.h>
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#include "../kselftest.h"
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#define NSEC_PER_SEC 1000000000ULL
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#define TARGET_TIMEOUT 100000000 /* 100ms in nanoseconds */
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#define UNRESONABLE_LATENCY 40000000 /* 40ms in nanosecs */
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long long timespec_sub(struct timespec a, struct timespec b)
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{
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long long ret = NSEC_PER_SEC * b.tv_sec + b.tv_nsec;
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ret -= NSEC_PER_SEC * a.tv_sec + a.tv_nsec;
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return ret;
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}
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struct timespec timespec_add(struct timespec ts, unsigned long long ns)
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{
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ts.tv_nsec += ns;
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while (ts.tv_nsec >= NSEC_PER_SEC) {
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ts.tv_nsec -= NSEC_PER_SEC;
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ts.tv_sec++;
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}
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return ts;
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}
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int mqueue_lat_test(void)
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{
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mqd_t q;
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struct mq_attr attr;
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struct timespec start, end, now, target;
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int i, count, ret;
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q = mq_open("/foo", O_CREAT | O_RDONLY, 0666, NULL);
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if (q < 0) {
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perror("mq_open");
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return -1;
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}
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mq_getattr(q, &attr);
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count = 100;
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clock_gettime(CLOCK_MONOTONIC, &start);
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for (i = 0; i < count; i++) {
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char buf[attr.mq_msgsize];
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clock_gettime(CLOCK_REALTIME, &now);
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target = now;
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target = timespec_add(now, TARGET_TIMEOUT); /* 100ms */
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ret = mq_timedreceive(q, buf, sizeof(buf), NULL, &target);
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if (ret < 0 && errno != ETIMEDOUT) {
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perror("mq_timedreceive");
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return -1;
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}
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}
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clock_gettime(CLOCK_MONOTONIC, &end);
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mq_close(q);
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if ((timespec_sub(start, end)/count) > TARGET_TIMEOUT + UNRESONABLE_LATENCY)
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return -1;
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return 0;
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}
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int main(int argc, char **argv)
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{
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int ret;
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printf("Mqueue latency : ");
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fflush(stdout);
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ret = mqueue_lat_test();
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if (ret < 0) {
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printf("[FAILED]\n");
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ksft_exit_fail();
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}
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printf("[OK]\n");
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ksft_exit_pass();
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}
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