X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=gettime.c;h=14462420219812266033a297d3c4d38f8fdc9006;hp=a4ee20df73b122c9a63cf7cd243e98e5186c1180;hb=HEAD;hpb=8b6a404cdd2c40715885e562416c3db039912773 diff --git a/gettime.c b/gettime.c index a4ee20df..5ca31206 100644 --- a/gettime.c +++ b/gettime.c @@ -2,33 +2,29 @@ * Clock functions */ -#include #include -#include -#include #include "fio.h" -#include "smalloc.h" - -#include "hash.h" #include "os/os.h" #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_nsec; -static uint64_t max_cycles_for_mult; -#define NSEC_INV_FACTOR 4096 +static unsigned long long cycles_per_msec; +static unsigned long long cycles_start; +static unsigned long long clock_mult; +static unsigned long long max_cycles_mask; +static unsigned long long nsecs_for_max_cycles; +static unsigned int clock_shift; +static unsigned int max_cycles_shift; +#define MAX_CLOCK_SEC 60*60 #endif #ifdef ARCH_CPU_CLOCK_WRAPS -static unsigned long long cycles_start, cycles_wrap; +static unsigned int cycles_wrap; #endif #endif -int tsc_reliable = 0; +bool tsc_reliable = false; struct tv_valid { - uint64_t last_cycles; - int last_tv_valid; int warned; }; #ifdef ARCH_HAVE_CPU_CLOCK @@ -131,18 +127,33 @@ static void fio_init gtod_init(void) #endif /* FIO_DEBUG_TIME */ -#ifdef CONFIG_CLOCK_GETTIME -static int fill_clock_gettime(struct timespec *ts) +/* + * Queries the value of the monotonic clock if a monotonic clock is available + * or the wall clock time if no monotonic clock is available. Returns 0 if + * querying the clock succeeded or -1 if querying the clock failed. + */ +int fio_get_mono_time(struct timespec *ts) { -#if defined(CONFIG_CLOCK_MONOTONIC_RAW) - return clock_gettime(CLOCK_MONOTONIC_RAW, ts); -#elif defined(CONFIG_CLOCK_MONOTONIC) - return clock_gettime(CLOCK_MONOTONIC, ts); + int ret; + +#ifdef CONFIG_CLOCK_GETTIME +#if defined(CONFIG_CLOCK_MONOTONIC) + ret = clock_gettime(CLOCK_MONOTONIC, ts); #else - return clock_gettime(CLOCK_REALTIME, ts); + ret = clock_gettime(CLOCK_REALTIME, ts); #endif -} +#else + struct timeval tv; + + ret = gettimeofday(&tv, NULL); + if (ret == 0) { + ts->tv_sec = tv.tv_sec; + ts->tv_nsec = tv.tv_usec * 1000; + } #endif + assert(ret <= 0); + return ret; +} static void __fio_gettime(struct timespec *tp) { @@ -159,8 +170,8 @@ static void __fio_gettime(struct timespec *tp) #endif #ifdef CONFIG_CLOCK_GETTIME case CS_CGETTIME: { - if (fill_clock_gettime(tp) < 0) { - log_err("fio: clock_gettime fails\n"); + if (fio_get_mono_time(tp) < 0) { + log_err("fio: fio_get_mono_time() fails\n"); assert(0); } break; @@ -168,7 +179,7 @@ static void __fio_gettime(struct timespec *tp) #endif #ifdef ARCH_HAVE_CPU_CLOCK case CS_CPUCLOCK: { - uint64_t nsecs, t; + uint64_t nsecs, t, multiples; struct tv_valid *tv; #ifdef CONFIG_TLS_THREAD @@ -185,18 +196,14 @@ static void __fio_gettime(struct timespec *tp) 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 - nsecs = t * 1000 / ARCH_CPU_CLOCK_CYCLES_PER_USEC; + nsecs = t / ARCH_CPU_CLOCK_CYCLES_PER_USEC * 1000; #else - if (t < max_cycles_for_mult) - nsecs = (t * inv_cycles_per_nsec) / NSEC_INV_FACTOR; - else - nsecs = (t / NSEC_INV_FACTOR) * inv_cycles_per_nsec; + t -= cycles_start; + multiples = t >> max_cycles_shift; + nsecs = multiples * nsecs_for_max_cycles; + nsecs += ((t & max_cycles_mask) * clock_mult) >> clock_shift; #endif tp->tv_sec = nsecs / 1000000000ULL; tp->tv_nsec = nsecs % 1000000000ULL; @@ -228,33 +235,25 @@ void fio_gettime(struct timespec *tp, void fio_unused *caller) } #if defined(ARCH_HAVE_CPU_CLOCK) && !defined(ARCH_CPU_CLOCK_CYCLES_PER_USEC) -static unsigned long get_cycles_per_usec(void) +static unsigned long get_cycles_per_msec(void) { struct timespec 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; -#else - fio_clock_source = CS_GTOD; -#endif - __fio_gettime(&s); + fio_get_mono_time(&s); c_s = get_cpu_clock(); do { - __fio_gettime(&e); + fio_get_mono_time(&e); + c_e = get_cpu_clock(); - elapsed = utime_since(&s, &e); - if (elapsed >= 1280) { - c_e = get_cpu_clock(); + elapsed = ntime_since(&s, &e); + if (elapsed >= 1280000) break; - } } while (1); - fio_clock_source = old_cs; - return (c_e - c_s) / elapsed; + return (c_e - c_s) * 1000000 / elapsed; } #define NR_TIME_ITERS 50 @@ -263,12 +262,13 @@ static int calibrate_cpu_clock(void) { double delta, mean, S; uint64_t minc, maxc, avg, cycles[NR_TIME_ITERS]; - int i, samples; + int i, samples, sft = 0; + unsigned long long tmp, max_ticks, max_mult; - cycles[0] = get_cycles_per_usec(); + cycles[0] = get_cycles_per_msec(); S = delta = mean = 0.0; for (i = 0; i < NR_TIME_ITERS; i++) { - cycles[i] = get_cycles_per_usec(); + cycles[i] = get_cycles_per_msec(); delta = cycles[i] - mean; if (delta) { mean += delta / (i + 1.0); @@ -305,19 +305,67 @@ static int calibrate_cpu_clock(void) dprint(FD_TIME, "cycles[%d]=%llu\n", i, (unsigned long long) cycles[i]); avg /= samples; - dprint(FD_TIME, "avg: %llu\n", (unsigned long long) avg); - dprint(FD_TIME, "min=%llu, max=%llu, mean=%f, S=%f\n", + cycles_per_msec = avg; + dprint(FD_TIME, "min=%llu, max=%llu, mean=%f, S=%f, N=%d\n", (unsigned long long) minc, - (unsigned long long) maxc, mean, S); + (unsigned long long) maxc, mean, S, NR_TIME_ITERS); + dprint(FD_TIME, "trimmed mean=%llu, N=%d\n", (unsigned long long) avg, samples); + + max_ticks = MAX_CLOCK_SEC * cycles_per_msec * 1000ULL; + max_mult = ULLONG_MAX / max_ticks; + dprint(FD_TIME, "max_ticks=%llu, __builtin_clzll=%d, " + "max_mult=%llu\n", max_ticks, + __builtin_clzll(max_ticks), max_mult); + + /* + * Find the largest shift count that will produce + * a multiplier that does not exceed max_mult + */ + tmp = max_mult * cycles_per_msec / 1000000; + while (tmp > 1) { + tmp >>= 1; + sft++; + dprint(FD_TIME, "tmp=%llu, sft=%u\n", tmp, sft); + } + + clock_shift = sft; + clock_mult = (1ULL << sft) * 1000000 / cycles_per_msec; + dprint(FD_TIME, "clock_shift=%u, clock_mult=%llu\n", clock_shift, + clock_mult); + + /* + * Find the greatest power of 2 clock ticks that is less than the + * ticks in MAX_CLOCK_SEC + */ + max_cycles_shift = max_cycles_mask = 0; + tmp = MAX_CLOCK_SEC * 1000ULL * cycles_per_msec; + dprint(FD_TIME, "tmp=%llu, max_cycles_shift=%u\n", tmp, + max_cycles_shift); + while (tmp > 1) { + tmp >>= 1; + max_cycles_shift++; + dprint(FD_TIME, "tmp=%llu, max_cycles_shift=%u\n", tmp, max_cycles_shift); + } + /* + * if use use (1ULL << max_cycles_shift) * 1000 / cycles_per_msec + * here we will have a discontinuity every + * (1ULL << max_cycles_shift) cycles + */ + nsecs_for_max_cycles = ((1ULL << max_cycles_shift) * clock_mult) + >> clock_shift; + + /* Use a bitmask to calculate ticks % (1ULL << max_cycles_shift) */ + for (tmp = 0; tmp < max_cycles_shift; tmp++) + max_cycles_mask |= 1ULL << tmp; + + dprint(FD_TIME, "max_cycles_shift=%u, 2^max_cycles_shift=%llu, " + "nsecs_for_max_cycles=%llu, " + "max_cycles_mask=%016llx\n", + max_cycles_shift, (1ULL << max_cycles_shift), + nsecs_for_max_cycles, max_cycles_mask); - cycles_per_usec = avg; - inv_cycles_per_nsec = NSEC_INV_FACTOR * 1000 / cycles_per_usec; - max_cycles_for_mult = ~0ULL / inv_cycles_per_nsec; - dprint(FD_TIME, "inv_cycles_per_nsec=%lu\n", inv_cycles_per_nsec); -#ifdef ARCH_CPU_CLOCK_WRAPS cycles_start = get_cpu_clock(); dprint(FD_TIME, "cycles_start=%llu\n", cycles_start); -#endif return 0; } #else @@ -331,8 +379,8 @@ static int calibrate_cpu_clock(void) } #endif // ARCH_HAVE_CPU_CLOCK -#ifndef CONFIG_TLS_THREAD -void fio_local_clock_init(int is_thread) +#if defined(ARCH_HAVE_CPU_CLOCK) && !defined(CONFIG_TLS_THREAD) +void fio_local_clock_init(void) { struct tv_valid *t; @@ -348,7 +396,7 @@ static void kill_tv_tls_key(void *data) free(data); } #else -void fio_local_clock_init(int is_thread) +void fio_local_clock_init(void) { } #endif @@ -358,7 +406,7 @@ void fio_clock_init(void) if (fio_clock_source == fio_clock_source_inited) return; -#ifndef CONFIG_TLS_THREAD +#if defined(ARCH_HAVE_CPU_CLOCK) && !defined(CONFIG_TLS_THREAD) if (pthread_key_create(&tv_tls_key, kill_tv_tls_key)) log_err("fio: can't create TLS key\n"); #endif @@ -366,7 +414,7 @@ void fio_clock_init(void) fio_clock_source_inited = fio_clock_source; if (calibrate_cpu_clock()) - tsc_reliable = 0; + tsc_reliable = false; /* * If the arch sets tsc_reliable != 0, then it must be good enough @@ -378,6 +426,35 @@ void fio_clock_init(void) fio_clock_source = CS_CPUCLOCK; } else if (fio_clock_source == CS_CPUCLOCK) log_info("fio: clocksource=cpu may not be reliable\n"); + dprint(FD_TIME, "gettime: clocksource=%d\n", (int) fio_clock_source); +} + +uint64_t ntime_since(const struct timespec *s, const struct timespec *e) +{ + int64_t sec, nsec; + + sec = e->tv_sec - s->tv_sec; + nsec = e->tv_nsec - s->tv_nsec; + if (sec > 0 && nsec < 0) { + sec--; + nsec += 1000000000LL; + } + + /* + * time warp bug on some kernels? + */ + if (sec < 0 || (sec == 0 && nsec < 0)) + return 0; + + return nsec + (sec * 1000000000LL); +} + +uint64_t ntime_since_now(const struct timespec *s) +{ + struct timespec now; + + fio_gettime(&now, NULL); + return ntime_since(s, &now); } uint64_t utime_since(const struct timespec *s, const struct timespec *e) @@ -447,23 +524,33 @@ uint64_t mtime_since_now(const struct timespec *s) return mtime_since(s, &t); } -uint64_t mtime_since(const struct timespec *s, const struct timespec *e) +/* + * Returns *e - *s in milliseconds as a signed integer. Note: rounding is + * asymmetric. If the difference yields +1 ns then 0 is returned. If the + * difference yields -1 ns then -1 is returned. + */ +int64_t rel_time_since(const struct timespec *s, const struct timespec *e) { - int64_t sec, usec; + int64_t sec, nsec; sec = e->tv_sec - s->tv_sec; - usec = (e->tv_nsec - s->tv_nsec) / 1000; - if (sec > 0 && usec < 0) { + nsec = e->tv_nsec - s->tv_nsec; + if (nsec < 0) { sec--; - usec += 1000000; + nsec += 1000ULL * 1000 * 1000; } + assert(0 <= nsec && nsec < 1000ULL * 1000 * 1000); - if (sec < 0 || (sec == 0 && usec < 0)) - return 0; + return sec * 1000 + nsec / (1000 * 1000); +} - sec *= 1000; - usec /= 1000; - return sec + usec; +/* + * Returns *e - *s in milliseconds as an unsigned integer. Returns 0 if + * *e < *s. + */ +uint64_t mtime_since(const struct timespec *s, const struct timespec *e) +{ + return max(rel_time_since(s, e), (int64_t)0); } uint64_t time_since_now(const struct timespec *s) @@ -472,10 +559,10 @@ uint64_t time_since_now(const struct timespec *s) } #if defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK) && \ - defined(CONFIG_SFAA) + defined(CONFIG_SYNC_SYNC) && defined(CONFIG_CMP_SWAP) #define CLOCK_ENTRIES_DEBUG 100000 -#define CLOCK_ENTRIES_TEST 10000 +#define CLOCK_ENTRIES_TEST 1000 struct clock_entry { uint32_t seq; @@ -487,16 +574,16 @@ struct clock_thread { pthread_t thread; int cpu; int debug; - pthread_mutex_t lock; - pthread_mutex_t started; + struct fio_sem lock; unsigned long nr_entries; uint32_t *seq; struct clock_entry *entries; }; -static inline uint32_t atomic32_inc_return(uint32_t *seq) +static inline uint32_t atomic32_compare_and_swap(uint32_t *ptr, uint32_t old, + uint32_t new) { - return 1 + __sync_fetch_and_add(seq, 1); + return __sync_val_compare_and_swap(ptr, old, new); } static void *clock_thread_fn(void *data) @@ -504,7 +591,6 @@ static void *clock_thread_fn(void *data) struct clock_thread *t = data; struct clock_entry *c; os_cpu_mask_t cpu_mask; - uint32_t last_seq; unsigned long long first; int i; @@ -524,11 +610,9 @@ static void *clock_thread_fn(void *data) goto err; } - pthread_mutex_lock(&t->lock); - pthread_mutex_unlock(&t->started); + fio_sem_down(&t->lock); first = get_cpu_clock(); - last_seq = 0; c = &t->entries[0]; for (i = 0; i < t->nr_entries; i++, c++) { uint32_t seq; @@ -536,11 +620,15 @@ static void *clock_thread_fn(void *data) c->cpu = t->cpu; do { - seq = atomic32_inc_return(t->seq); - if (seq < last_seq) + seq = *t->seq; + if (seq == UINT_MAX) break; + tsc_barrier(); tsc = get_cpu_clock(); - } while (seq != *t->seq); + } while (seq != atomic32_compare_and_swap(t->seq, seq, seq + 1)); + + if (seq == UINT_MAX) + break; c->seq = seq; c->tsc = tsc; @@ -558,7 +646,7 @@ static void *clock_thread_fn(void *data) * 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) + if (i > 1 && !t->entries[i - 1].tsc && !t->entries[0].tsc) goto err; fio_cpuset_exit(&cpu_mask); @@ -583,12 +671,21 @@ static int clock_cmp(const void *p1, const void *p2) int fio_monotonic_clocktest(int debug) { struct clock_thread *cthreads; - unsigned int nr_cpus = cpus_online(); + unsigned int seen_cpus, nr_cpus = cpus_configured(); struct clock_entry *entries; unsigned long nr_entries, tentries, failed = 0; struct clock_entry *prev, *this; uint32_t seq = 0; unsigned int i; + os_cpu_mask_t mask; + +#ifdef FIO_HAVE_GET_THREAD_AFFINITY + fio_get_thread_affinity(mask); +#else + memset(&mask, 0, sizeof(mask)); + for (i = 0; i < nr_cpus; i++) + fio_cpu_set(&mask, i); +#endif if (debug) { log_info("cs: reliable_tsc: %s\n", tsc_reliable ? "yes" : "no"); @@ -615,43 +712,44 @@ int fio_monotonic_clocktest(int debug) if (debug) log_info("cs: Testing %u CPUs\n", nr_cpus); + seen_cpus = 0; for (i = 0; i < nr_cpus; i++) { struct clock_thread *t = &cthreads[i]; + if (!fio_cpu_isset(&mask, i)) + continue; t->cpu = i; t->debug = debug; t->seq = &seq; 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); + t->entries = &entries[seen_cpus * nr_entries]; + __fio_sem_init(&t->lock, FIO_SEM_LOCKED); if (pthread_create(&t->thread, NULL, clock_thread_fn, t)) { failed++; nr_cpus = i; break; } + seen_cpus++; } for (i = 0; i < nr_cpus; i++) { struct clock_thread *t = &cthreads[i]; - pthread_mutex_lock(&t->started); - } - - for (i = 0; i < nr_cpus; i++) { - struct clock_thread *t = &cthreads[i]; - - pthread_mutex_unlock(&t->lock); + if (!fio_cpu_isset(&mask, i)) + continue; + fio_sem_up(&t->lock); } for (i = 0; i < nr_cpus; i++) { struct clock_thread *t = &cthreads[i]; void *ret; + if (!fio_cpu_isset(&mask, i)) + continue; pthread_join(t->thread, &ret); if (ret) failed++; + __fio_sem_remove(&t->lock); } free(cthreads); @@ -661,6 +759,7 @@ int fio_monotonic_clocktest(int debug) goto err; } + tentries = nr_entries * seen_cpus; qsort(entries, tentries, sizeof(struct clock_entry), clock_cmp); /* silence silly gcc */