X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=gettime.c;h=b896b5bd9923e7b818e9e88fe99eb0a369dd9f63;hp=6a7e35f87249905c044165bfe1869f4ac0605e99;hb=13aa415afc8d0a2ad0de2d6c17d6bca2d16f00c7;hpb=8a1db9a16e1075498e5d6166fa46b419cecd8af8 diff --git a/gettime.c b/gettime.c index 6a7e35f8..b896b5bd 100644 --- a/gettime.c +++ b/gettime.c @@ -13,22 +13,30 @@ #include "hash.h" #include "os/os.h" -#if defined(ARCH_HAVE_CPU_CLOCK) && !defined(ARCH_CPU_CLOCK_CYCLES_PER_USEC) +#if defined(ARCH_HAVE_CPU_CLOCK) +#ifndef ARCH_CPU_CLOCK_CYCLES_PER_USEC static unsigned long cycles_per_usec; static unsigned long inv_cycles_per_usec; +static uint64_t max_cycles_for_mult; +#endif +#ifdef ARCH_CPU_CLOCK_WRAPS +static unsigned long long cycles_start, cycles_wrap; +#endif #endif int tsc_reliable = 0; struct tv_valid { - struct timeval last_tv; uint64_t last_cycles; int last_tv_valid; + int warned; }; +#ifdef ARCH_HAVE_CPU_CLOCK #ifdef CONFIG_TLS_THREAD static __thread struct tv_valid static_tv_valid; #else static pthread_key_t tv_tls_key; #endif +#endif enum fio_cs fio_clock_source = FIO_PREFERRED_CLOCK_SOURCE; int fio_clock_source_set = 0; @@ -64,7 +72,7 @@ static struct gtod_log *find_hash(void *caller) return NULL; } -static struct gtod_log *find_log(void *caller) +static void inc_caller(void *caller) { struct gtod_log *log = find_hash(caller); @@ -80,16 +88,13 @@ static struct gtod_log *find_log(void *caller) flist_add_tail(&log->list, &hash[h]); } - return log; + log->calls++; } static void gtod_log_caller(void *caller) { - if (gtod_inited) { - struct gtod_log *log = find_log(caller); - - log->calls++; - } + if (gtod_inited) + inc_caller(caller); } static void fio_exit fio_dump_gtod(void) @@ -128,7 +133,9 @@ static void fio_init gtod_init(void) #ifdef CONFIG_CLOCK_GETTIME static int fill_clock_gettime(struct timespec *ts) { -#ifdef CONFIG_CLOCK_MONOTONIC +#if defined(CONFIG_CLOCK_MONOTONIC_RAW) + return clock_gettime(CLOCK_MONOTONIC_RAW, ts); +#elif defined(CONFIG_CLOCK_MONOTONIC) return clock_gettime(CLOCK_MONOTONIC, ts); #else return clock_gettime(CLOCK_REALTIME, ts); @@ -136,16 +143,8 @@ static int fill_clock_gettime(struct timespec *ts) } #endif -static void *__fio_gettime(struct timeval *tp) +static void __fio_gettime(struct timeval *tp) { - struct tv_valid *tv; - -#ifdef CONFIG_TLS_THREAD - tv = &static_tv_valid; -#else - tv = pthread_getspecific(tv_tls_key); -#endif - switch (fio_clock_source) { #ifdef CONFIG_GETTIMEOFDAY case CS_GTOD: @@ -169,18 +168,34 @@ static void *__fio_gettime(struct timeval *tp) #ifdef ARCH_HAVE_CPU_CLOCK case CS_CPUCLOCK: { uint64_t usecs, t; + struct tv_valid *tv; + +#ifdef CONFIG_TLS_THREAD + tv = &static_tv_valid; +#else + tv = pthread_getspecific(tv_tls_key); +#endif t = get_cpu_clock(); - if (tv && t < tv->last_cycles) { - dprint(FD_TIME, "CPU clock going back in time\n"); - t = tv->last_cycles; - } else if (tv) - tv->last_cycles = t; +#ifdef ARCH_CPU_CLOCK_WRAPS + if (t < cycles_start && !cycles_wrap) + cycles_wrap = 1; + else if (cycles_wrap && t >= cycles_start && !tv->warned) { + log_err("fio: double CPU clock wrap\n"); + tv->warned = 1; + } + t -= cycles_start; +#endif + tv->last_cycles = t; + tv->last_tv_valid = 1; #ifdef ARCH_CPU_CLOCK_CYCLES_PER_USEC usecs = t / ARCH_CPU_CLOCK_CYCLES_PER_USEC; #else - usecs = (t * inv_cycles_per_usec) / 16777216UL; + if (t < max_cycles_for_mult) + usecs = (t * inv_cycles_per_usec) / 16777216UL; + else + usecs = t / cycles_per_usec; #endif tp->tv_sec = usecs / 1000000; tp->tv_usec = usecs % 1000000; @@ -191,8 +206,6 @@ static void *__fio_gettime(struct timeval *tp) log_err("fio: invalid clock source %d\n", fio_clock_source); break; } - - return tv; } #ifdef FIO_DEBUG_TIME @@ -201,36 +214,16 @@ void fio_gettime(struct timeval *tp, void *caller) void fio_gettime(struct timeval *tp, void fio_unused *caller) #endif { - struct tv_valid *tv; - #ifdef FIO_DEBUG_TIME if (!caller) caller = __builtin_return_address(0); gtod_log_caller(caller); #endif - if (fio_unlikely(fio_tv)) { - memcpy(tp, fio_tv, sizeof(*tp)); + if (fio_unlikely(fio_gettime_offload(tp))) return; - } - tv = __fio_gettime(tp); - - /* - * If Linux is using the tsc clock on non-synced processors, - * sometimes time can appear to drift backwards. Fix that up. - */ - if (tv) { - if (tv->last_tv_valid) { - if (tp->tv_sec < tv->last_tv.tv_sec) - tp->tv_sec = tv->last_tv.tv_sec; - else if (tv->last_tv.tv_sec == tp->tv_sec && - tp->tv_usec < tv->last_tv.tv_usec) - tp->tv_usec = tv->last_tv.tv_usec; - } - tv->last_tv_valid = 1; - memcpy(&tv->last_tv, tp, sizeof(*tp)); - } + __fio_gettime(tp); } #if defined(ARCH_HAVE_CPU_CLOCK) && !defined(ARCH_CPU_CLOCK_CYCLES_PER_USEC) @@ -239,6 +232,7 @@ static unsigned long get_cycles_per_usec(void) struct timeval s, e; uint64_t c_s, c_e; enum fio_cs old_cs = fio_clock_source; + uint64_t elapsed; #ifdef CONFIG_CLOCK_GETTIME fio_clock_source = CS_CGETTIME; @@ -249,8 +243,6 @@ static unsigned long get_cycles_per_usec(void) c_s = get_cpu_clock(); do { - uint64_t elapsed; - __fio_gettime(&e); elapsed = utime_since(&s, &e); @@ -261,7 +253,7 @@ static unsigned long get_cycles_per_usec(void) } while (1); fio_clock_source = old_cs; - return (c_e - c_s + 127) >> 7; + return (c_e - c_s) / elapsed; } #define NR_TIME_ITERS 50 @@ -269,7 +261,7 @@ static unsigned long get_cycles_per_usec(void) static int calibrate_cpu_clock(void) { double delta, mean, S; - uint64_t avg, cycles[NR_TIME_ITERS]; + uint64_t minc, maxc, avg, cycles[NR_TIME_ITERS]; int i, samples; cycles[0] = get_cycles_per_usec(); @@ -292,10 +284,14 @@ static int calibrate_cpu_clock(void) S = sqrt(S / (NR_TIME_ITERS - 1.0)); - samples = avg = 0; + minc = -1ULL; + maxc = samples = avg = 0; for (i = 0; i < NR_TIME_ITERS; i++) { double this = cycles[i]; + minc = min(cycles[i], minc); + maxc = max(cycles[i], maxc); + if ((fmax(this, mean) - fmin(this, mean)) > S) continue; samples++; @@ -303,20 +299,24 @@ static int calibrate_cpu_clock(void) } S /= (double) NR_TIME_ITERS; - mean /= 10.0; for (i = 0; i < NR_TIME_ITERS; i++) - dprint(FD_TIME, "cycles[%d]=%llu\n", i, - (unsigned long long) cycles[i] / 10); + dprint(FD_TIME, "cycles[%d]=%llu\n", i, (unsigned long long) cycles[i]); avg /= samples; - avg = (avg + 5) / 10; dprint(FD_TIME, "avg: %llu\n", (unsigned long long) avg); - dprint(FD_TIME, "mean=%f, S=%f\n", mean, S); + dprint(FD_TIME, "min=%llu, max=%llu, mean=%f, S=%f\n", + (unsigned long long) minc, + (unsigned long long) maxc, mean, S); cycles_per_usec = avg; inv_cycles_per_usec = 16777216UL / cycles_per_usec; + max_cycles_for_mult = ~0ULL / inv_cycles_per_usec; dprint(FD_TIME, "inv_cycles_per_usec=%lu\n", inv_cycles_per_usec); +#ifdef ARCH_CPU_CLOCK_WRAPS + cycles_start = get_cpu_clock(); + dprint(FD_TIME, "cycles_start=%llu\n", cycles_start); +#endif return 0; } #else @@ -336,8 +336,10 @@ void fio_local_clock_init(int is_thread) struct tv_valid *t; t = calloc(1, sizeof(*t)); - if (pthread_setspecific(tv_tls_key, t)) + if (pthread_setspecific(tv_tls_key, t)) { log_err("fio: can't set TLS key\n"); + assert(0); + } } static void kill_tv_tls_key(void *data) @@ -371,7 +373,7 @@ void fio_clock_init(void) * runs at a constant rate and is synced across CPU cores. */ if (tsc_reliable) { - if (!fio_clock_source_set) + if (!fio_clock_source_set && !fio_monotonic_clocktest(0)) fio_clock_source = CS_CPUCLOCK; } else if (fio_clock_source == CS_CPUCLOCK) log_info("fio: clocksource=cpu may not be reliable\n"); @@ -446,7 +448,8 @@ uint64_t time_since_now(const struct timeval *s) #if defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK) && \ defined(CONFIG_SFAA) -#define CLOCK_ENTRIES 100000 +#define CLOCK_ENTRIES_DEBUG 100000 +#define CLOCK_ENTRIES_TEST 10000 struct clock_entry { uint32_t seq; @@ -457,8 +460,10 @@ struct clock_entry { struct clock_thread { pthread_t thread; int cpu; + int debug; pthread_mutex_t lock; pthread_mutex_t started; + unsigned long nr_entries; uint32_t *seq; struct clock_entry *entries; }; @@ -474,22 +479,32 @@ static void *clock_thread_fn(void *data) struct clock_entry *c; os_cpu_mask_t cpu_mask; uint32_t last_seq; + unsigned long long first; int i; - memset(&cpu_mask, 0, sizeof(cpu_mask)); + if (fio_cpuset_init(&cpu_mask)) { + int __err = errno; + + log_err("clock cpuset init failed: %s\n", strerror(__err)); + goto err_out; + } + fio_cpu_set(&cpu_mask, t->cpu); if (fio_setaffinity(gettid(), cpu_mask) == -1) { - log_err("clock setaffinity failed\n"); - return (void *) 1; + int __err = errno; + + log_err("clock setaffinity failed: %s\n", strerror(__err)); + goto err; } pthread_mutex_lock(&t->lock); pthread_mutex_unlock(&t->started); + first = get_cpu_clock(); last_seq = 0; c = &t->entries[0]; - for (i = 0; i < CLOCK_ENTRIES; i++, c++) { + for (i = 0; i < t->nr_entries; i++, c++) { uint32_t seq; uint64_t tsc; @@ -505,17 +520,27 @@ static void *clock_thread_fn(void *data) c->tsc = tsc; } - log_info("cs: cpu%3d: %llu clocks seen\n", t->cpu, - (unsigned long long) t->entries[i - 1].tsc - t->entries[0].tsc); + if (t->debug) { + unsigned long long clocks; + + clocks = t->entries[i - 1].tsc - t->entries[0].tsc; + log_info("cs: cpu%3d: %llu clocks seen, first %llu\n", t->cpu, + clocks, first); + } /* * The most common platform clock breakage is returning zero * indefinitely. Check for that and return failure. */ if (!t->entries[i - 1].tsc && !t->entries[0].tsc) - return (void *) 1; + goto err; + fio_cpuset_exit(&cpu_mask); return NULL; +err: + fio_cpuset_exit(&cpu_mask); +err_out: + return (void *) 1; } static int clock_cmp(const void *p1, const void *p2) @@ -529,38 +554,49 @@ static int clock_cmp(const void *p1, const void *p2) return c1->seq - c2->seq; } -int fio_monotonic_clocktest(void) +int fio_monotonic_clocktest(int debug) { struct clock_thread *cthreads; unsigned int nr_cpus = cpus_online(); struct clock_entry *entries; - unsigned long tentries, failed = 0; + unsigned long nr_entries, tentries, failed = 0; struct clock_entry *prev, *this; uint32_t seq = 0; unsigned int i; - log_info("cs: reliable_tsc: %s\n", tsc_reliable ? "yes" : "no"); + if (debug) { + log_info("cs: reliable_tsc: %s\n", tsc_reliable ? "yes" : "no"); #ifdef FIO_INC_DEBUG - fio_debug |= 1U << FD_TIME; + fio_debug |= 1U << FD_TIME; #endif + nr_entries = CLOCK_ENTRIES_DEBUG; + } else + nr_entries = CLOCK_ENTRIES_TEST; + calibrate_cpu_clock(); + + if (debug) { #ifdef FIO_INC_DEBUG - fio_debug &= ~(1U << FD_TIME); + fio_debug &= ~(1U << FD_TIME); #endif + } cthreads = malloc(nr_cpus * sizeof(struct clock_thread)); - tentries = CLOCK_ENTRIES * nr_cpus; + tentries = nr_entries * nr_cpus; entries = malloc(tentries * sizeof(struct clock_entry)); - log_info("cs: Testing %u CPUs\n", nr_cpus); + if (debug) + log_info("cs: Testing %u CPUs\n", nr_cpus); for (i = 0; i < nr_cpus; i++) { struct clock_thread *t = &cthreads[i]; t->cpu = i; + t->debug = debug; t->seq = &seq; - t->entries = &entries[i * CLOCK_ENTRIES]; + t->nr_entries = nr_entries; + t->entries = &entries[i * nr_entries]; pthread_mutex_init(&t->lock, NULL); pthread_mutex_init(&t->started, NULL); pthread_mutex_lock(&t->lock); @@ -594,12 +630,15 @@ int fio_monotonic_clocktest(void) free(cthreads); if (failed) { - log_err("Clocksource test: %lu threads failed\n", failed); + if (debug) + log_err("Clocksource test: %lu threads failed\n", failed); goto err; } qsort(entries, tentries, sizeof(struct clock_entry), clock_cmp); + /* silence silly gcc */ + prev = NULL; for (failed = i = 0; i < tentries; i++) { this = &entries[i]; @@ -611,6 +650,11 @@ int fio_monotonic_clocktest(void) if (prev->tsc > this->tsc) { uint64_t diff = prev->tsc - this->tsc; + if (!debug) { + failed++; + break; + } + log_info("cs: CPU clock mismatch (diff=%llu):\n", (unsigned long long) diff); log_info("\t CPU%3u: TSC=%llu, SEQ=%u\n", prev->cpu, (unsigned long long) prev->tsc, prev->seq); @@ -621,11 +665,12 @@ int fio_monotonic_clocktest(void) prev = this; } - if (failed) - log_info("cs: Failed: %lu\n", failed); - else - log_info("cs: Pass!\n"); - + if (debug) { + if (failed) + log_info("cs: Failed: %lu\n", failed); + else + log_info("cs: Pass!\n"); + } err: free(entries); return !!failed; @@ -633,10 +678,11 @@ err: #else /* defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK) */ -int fio_monotonic_clocktest(void) +int fio_monotonic_clocktest(int debug) { - log_info("cs: current platform does not support CPU clocks\n"); - return 0; + if (debug) + log_info("cs: current platform does not support CPU clocks\n"); + return 1; } #endif