Files
linux/tools/testing/selftests/timers/mqueue-lat.c
Bala-Vignesh-Reddy e6fbd1759c selftests: complete kselftest include centralization
This follow-up patch completes centralization of kselftest.h and
ksefltest_harness.h includes in remaining seltests files, replacing all
relative paths with a non-relative paths using shared -I include path in
lib.mk

Tested with gcc-13.3 and clang-18.1, and cross-compiled successfully on
riscv, arm64, x86_64 and powerpc arch.

[reddybalavignesh9979@gmail.com: add selftests include path for kselftest.h]
  Link: https://lkml.kernel.org/r/20251017090201.317521-1-reddybalavignesh9979@gmail.com
Link: https://lkml.kernel.org/r/20251016104409.68985-1-reddybalavignesh9979@gmail.com
Signed-off-by: Bala-Vignesh-Reddy <reddybalavignesh9979@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/lkml/20250820143954.33d95635e504e94df01930d0@linux-foundation.org/
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Günther Noack <gnoack@google.com>
Cc: Jakub Kacinski <kuba@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mickael Salaun <mic@digikod.net>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Simon Horman <horms@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27 14:24:31 -08:00

115 lines
2.6 KiB
C

/* 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>
#include <include/vdso/time64.h>
#include "kselftest.h"
#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 : ");
fflush(stdout);
ret = mqueue_lat_test();
if (ret < 0) {
printf("[FAILED]\n");
ksft_exit_fail();
}
printf("[OK]\n");
ksft_exit_pass();
}