From 274d631e481504e347b491ddb5e18487b855aba5 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 11 Mar 2015 17:40:05 -0700 Subject: [PATCH] selftests/timers: Add mqueue latency test from the timetest suite Add test to validate mqueue timeout latency from the timetest suite Cc: Shuah Khan Cc: Prarit Bhargava Cc: Thomas Gleixner Cc: Richard Cochran Signed-off-by: John Stultz Tested-by: Prarit Bhargava Signed-off-by: Shuah Khan --- tools/testing/selftests/timers/Makefile | 3 +- tools/testing/selftests/timers/mqueue-lat.c | 124 ++++++++++++++++++++ 2 files changed, 126 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/timers/mqueue-lat.c 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 + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#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(); +} -- 2.20.1