/* * Copyright (C) 2013 Red Hat, Inc., Frederic Weisbecker * * Licensed under the terms of the GNU GPL License version 2 * * Selftests for a few posix timers interface. * * Kernel loop code stolen from Steven Rostedt */ #include #include #include #include #include #include #include "../kselftest.h" #define DELAY 2 #define USECS_PER_SEC 1000000 static volatile int done; /* Busy loop in userspace to elapse ITIMER_VIRTUAL */ static void user_loop(void) { while (!done); } /* * Try to spend as much time as possible in kernelspace * to elapse ITIMER_PROF. */ static void kernel_loop(void) { void *addr = sbrk(0); int err = 0; while (!done && !err) { err = brk(addr + 4096); err |= brk(addr); } } /* * Sleep until ITIMER_REAL expiration. */ static void idle_loop(void) { pause(); } static void sig_handler(int nr) { done = 1; } /* * Check the expected timer expiration matches the GTOD elapsed delta since * we armed the timer. Keep a 0.5 sec error margin due to various jitter. */ static int check_diff(struct timeval start, struct timeval end) { long long diff; diff = end.tv_usec - start.tv_usec; diff += (end.tv_sec - start.tv_sec) * USECS_PER_SEC; if (abs(diff - DELAY * USECS_PER_SEC) > USECS_PER_SEC / 2) { printf("Diff too high: %lld..", diff); return -1; } return 0; } static int check_itimer(int which) { int err; struct timeval start, end; struct itimerval val = { .it_value.tv_sec = DELAY, }; printf("Check itimer "); if (which == ITIMER_VIRTUAL) printf("virtual... "); else if (which == ITIMER_PROF) printf("prof... "); else if (which == ITIMER_REAL) printf("real... "); fflush(stdout); done = 0; if (which == ITIMER_VIRTUAL) signal(SIGVTALRM, sig_handler); else if (which == ITIMER_PROF) signal(SIGPROF, sig_handler); else if (which == ITIMER_REAL) signal(SIGALRM, sig_handler); err = gettimeofday(&start, NULL); if (err < 0) { perror("Can't call gettimeofday()\n"); return -1; } err = setitimer(which, &val, NULL); if (err < 0) { perror("Can't set timer\n"); return -1; } if (which == ITIMER_VIRTUAL) user_loop(); else if (which == ITIMER_PROF) kernel_loop(); else if (which == ITIMER_REAL) idle_loop(); err = gettimeofday(&end, NULL); if (err < 0) { perror("Can't call gettimeofday()\n"); return -1; } if (!check_diff(start, end)) printf("[OK]\n"); else printf("[FAIL]\n"); return 0; } static int check_timer_create(int which) { int err; timer_t id; struct timeval start, end; struct itimerspec val = { .it_value.tv_sec = DELAY, }; printf("Check timer_create() "); if (which == CLOCK_THREAD_CPUTIME_ID) { printf("per thread... "); } else if (which == CLOCK_PROCESS_CPUTIME_ID) { printf("per process... "); } fflush(stdout); done = 0; err = timer_create(which, NULL, &id); if (err < 0) { perror("Can't create timer\n"); return -1; } signal(SIGALRM, sig_handler); err = gettimeofday(&start, NULL); if (err < 0) { perror("Can't call gettimeofday()\n"); return -1; } err = timer_settime(id, 0, &val, NULL); if (err < 0) { perror("Can't set timer\n"); return -1; } user_loop(); err = gettimeofday(&end, NULL); if (err < 0) { perror("Can't call gettimeofday()\n"); return -1; } if (!check_diff(start, end)) printf("[OK]\n"); else printf("[FAIL]\n"); return 0; } int main(int argc, char **argv) { printf("Testing posix timers. False negative may happen on CPU execution \n"); printf("based timers if other threads run on the CPU...\n"); if (check_itimer(ITIMER_VIRTUAL) < 0) return ksft_exit_fail(); if (check_itimer(ITIMER_PROF) < 0) return ksft_exit_fail(); if (check_itimer(ITIMER_REAL) < 0) return ksft_exit_fail(); if (check_timer_create(CLOCK_THREAD_CPUTIME_ID) < 0) return ksft_exit_fail(); /* * It's unfortunately hard to reliably test a timer expiration * on parallel multithread cputime. We could arm it to expire * on DELAY * nr_threads, with nr_threads busy looping, then wait * the normal DELAY since the time is elapsing nr_threads faster. * But for that we need to ensure we have real physical free CPUs * to ensure true parallelism. So test only one thread until we * find a better solution. */ if (check_timer_create(CLOCK_PROCESS_CPUTIME_ID) < 0) return ksft_exit_fail(); return ksft_exit_pass(); } oonie@kernel.org>2016-11-04 12:15:25 -0600 commit1b5b42216469b05ef4b5916cb40b127dfab1da88 (patch) tree088f4074ec93c863025c27126c400f85009ad92a /net/ipv4 parent1001354ca34179f3db924eb66672442a173147dc (diff)
regulator: core: Add new API to poll for error conditions
Regulator consumers can receive event notifications when errors are reported to the driver, but currently, there is no way for a regulator consumer to know when the error is over. To allow a regulator consumer to poll for error conditions add a new API: regulator_get_error_flags. Signed-off-by: Axel Haslam <ahaslam@baylibre.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'net/ipv4')