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author | Dave Airlie <airlied@redhat.com> | 2015-04-20 11:32:26 +1000 |
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committer | Dave Airlie <airlied@redhat.com> | 2015-04-20 13:05:20 +1000 |
commit | 2c33ce009ca2389dbf0535d0672214d09738e35e (patch) | |
tree | 6186a6458c3c160385d794a23eaf07c786a9e61b /tools/testing/selftests/timers/mqueue-lat.c | |
parent | cec32a47010647e8b0603726ebb75b990a4057a4 (diff) | |
parent | 09d51602cf84a1264946711dd4ea0dddbac599a1 (diff) | |
download | linux-stable-2c33ce009ca2389dbf0535d0672214d09738e35e.tar.gz linux-stable-2c33ce009ca2389dbf0535d0672214d09738e35e.tar.bz2 linux-stable-2c33ce009ca2389dbf0535d0672214d09738e35e.zip |
Merge Linus master into drm-next
The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.
I've included the patch into the merge to fix the build.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'tools/testing/selftests/timers/mqueue-lat.c')
-rw-r--r-- | tools/testing/selftests/timers/mqueue-lat.c | 124 |
1 files changed, 124 insertions, 0 deletions
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(); +} |