*/
#include <unistd.h>
+#include <math.h>
#include <sys/time.h>
+#include <time.h>
#include "fio.h"
#include "smalloc.h"
#include "hash.h"
+#include "os/os.h"
-static int clock_gettime_works = 0;
-static struct timeval last_tv;
-static int last_tv_valid;
+#if defined(ARCH_HAVE_CPU_CLOCK) && !defined(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;
+static unsigned long long cycles_start, cycles_wrap;
+#endif
+int tsc_reliable = 0;
+
+struct tv_valid {
+ 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
-static struct timeval *fio_tv;
-int fio_gtod_offload = 0;
-int fio_gtod_cpu = -1;
+enum fio_cs fio_clock_source = FIO_PREFERRED_CLOCK_SOURCE;
+int fio_clock_source_set = 0;
+static enum fio_cs fio_clock_source_inited = CS_INVAL;
#ifdef FIO_DEBUG_TIME
return NULL;
}
-static struct gtod_log *find_log(void *caller)
+static void inc_caller(void *caller)
{
struct gtod_log *log = find_hash(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)
#endif /* FIO_DEBUG_TIME */
+#ifdef CONFIG_CLOCK_GETTIME
+static int fill_clock_gettime(struct timespec *ts)
+{
+#ifdef CONFIG_CLOCK_MONOTONIC
+ return clock_gettime(CLOCK_MONOTONIC, ts);
+#else
+ return clock_gettime(CLOCK_REALTIME, ts);
+#endif
+}
+#endif
+
+static void __fio_gettime(struct timeval *tp)
+{
+ switch (fio_clock_source) {
+#ifdef CONFIG_GETTIMEOFDAY
+ case CS_GTOD:
+ gettimeofday(tp, NULL);
+ break;
+#endif
+#ifdef CONFIG_CLOCK_GETTIME
+ case CS_CGETTIME: {
+ struct timespec ts;
+
+ if (fill_clock_gettime(&ts) < 0) {
+ log_err("fio: clock_gettime fails\n");
+ assert(0);
+ }
+
+ tp->tv_sec = ts.tv_sec;
+ tp->tv_usec = ts.tv_nsec / 1000;
+ break;
+ }
+#endif
+#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 (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;
+ 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
+ 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;
+ break;
+ }
+#endif
+ default:
+ log_err("fio: invalid clock source %d\n", fio_clock_source);
+ break;
+ }
+}
+
#ifdef FIO_DEBUG_TIME
void fio_gettime(struct timeval *tp, void *caller)
#else
gtod_log_caller(caller);
#endif
- if (fio_tv) {
- memcpy(tp, fio_tv, sizeof(*tp));
+ if (fio_unlikely(fio_gettime_offload(tp)))
return;
- } else if (!clock_gettime_works) {
-gtod:
- gettimeofday(tp, NULL);
- } else {
- struct timespec ts;
- if (clock_gettime(CLOCK_REALTIME, &ts) < 0) {
- clock_gettime_works = 0;
- goto gtod;
+ __fio_gettime(tp);
+}
+
+#if defined(ARCH_HAVE_CPU_CLOCK) && !defined(ARCH_CPU_CLOCK_CYCLES_PER_USEC)
+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;
+
+#ifdef CONFIG_CLOCK_GETTIME
+ fio_clock_source = CS_CGETTIME;
+#else
+ fio_clock_source = CS_GTOD;
+#endif
+ __fio_gettime(&s);
+
+ c_s = get_cpu_clock();
+ do {
+ uint64_t elapsed;
+
+ __fio_gettime(&e);
+
+ elapsed = utime_since(&s, &e);
+ if (elapsed >= 1280) {
+ c_e = get_cpu_clock();
+ break;
}
+ } while (1);
- tp->tv_sec = ts.tv_sec;
- tp->tv_usec = ts.tv_nsec / 1000;
+ fio_clock_source = old_cs;
+ return (c_e - c_s + 127) >> 7;
+}
+
+#define NR_TIME_ITERS 50
+
+static int calibrate_cpu_clock(void)
+{
+ double delta, mean, S;
+ uint64_t avg, cycles[NR_TIME_ITERS];
+ int i, samples;
+
+ cycles[0] = get_cycles_per_usec();
+ S = delta = mean = 0.0;
+ for (i = 0; i < NR_TIME_ITERS; i++) {
+ cycles[i] = get_cycles_per_usec();
+ delta = cycles[i] - mean;
+ if (delta) {
+ mean += delta / (i + 1.0);
+ S += delta * (cycles[i] - mean);
+ }
}
/*
- * If Linux is using the tsc clock on non-synced processors,
- * sometimes time can appear to drift backwards. Fix that up.
+ * The most common platform clock breakage is returning zero
+ * indefinitely. Check for that and return failure.
*/
- if (last_tv_valid) {
- if (tp->tv_sec < last_tv.tv_sec)
- tp->tv_sec = last_tv.tv_sec;
- else if (last_tv.tv_sec == tp->tv_sec &&
- tp->tv_usec < last_tv.tv_usec)
- tp->tv_usec = last_tv.tv_usec;
+ if (!cycles[0] && !cycles[NR_TIME_ITERS - 1])
+ return 1;
+
+ S = sqrt(S / (NR_TIME_ITERS - 1.0));
+
+ samples = avg = 0;
+ for (i = 0; i < NR_TIME_ITERS; i++) {
+ double this = cycles[i];
+
+ if ((fmax(this, mean) - fmin(this, mean)) > S)
+ continue;
+ samples++;
+ avg += this;
}
- last_tv_valid = 1;
- memcpy(&last_tv, tp, sizeof(*tp));
+
+ 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);
+
+ 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);
+
+ 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);
+ cycles_start = get_cpu_clock();
+ dprint(FD_TIME, "cycles_start=%llu\n", cycles_start);
+ return 0;
}
+#else
+static int calibrate_cpu_clock(void)
+{
+#ifdef ARCH_CPU_CLOCK_CYCLES_PER_USEC
+ return 0;
+#else
+ return 1;
+#endif
+}
+#endif // ARCH_HAVE_CPU_CLOCK
-void fio_gtod_init(void)
+#ifndef CONFIG_TLS_THREAD
+void fio_local_clock_init(int is_thread)
{
- fio_tv = smalloc(sizeof(struct timeval));
- assert(fio_tv);
+ struct tv_valid *t;
+
+ t = calloc(1, sizeof(*t));
+ if (pthread_setspecific(tv_tls_key, t)) {
+ log_err("fio: can't set TLS key\n");
+ assert(0);
+ }
}
-void fio_gtod_update(void)
+static void kill_tv_tls_key(void *data)
{
- gettimeofday(fio_tv, NULL);
+ free(data);
+}
+#else
+void fio_local_clock_init(int is_thread)
+{
+}
+#endif
+
+void fio_clock_init(void)
+{
+ if (fio_clock_source == fio_clock_source_inited)
+ return;
+
+#ifndef CONFIG_TLS_THREAD
+ if (pthread_key_create(&tv_tls_key, kill_tv_tls_key))
+ log_err("fio: can't create TLS key\n");
+#endif
+
+ fio_clock_source_inited = fio_clock_source;
+
+ if (calibrate_cpu_clock())
+ tsc_reliable = 0;
+
+ /*
+ * If the arch sets tsc_reliable != 0, then it must be good enough
+ * to use as THE clock source. For x86 CPUs, this means the TSC
+ * runs at a constant rate and is synced across CPU cores.
+ */
+ if (tsc_reliable) {
+ 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");
+}
+
+uint64_t utime_since(const struct timeval *s, const struct timeval *e)
+{
+ long sec, usec;
+ uint64_t ret;
+
+ sec = e->tv_sec - s->tv_sec;
+ usec = e->tv_usec - s->tv_usec;
+ if (sec > 0 && usec < 0) {
+ sec--;
+ usec += 1000000;
+ }
+
+ /*
+ * time warp bug on some kernels?
+ */
+ if (sec < 0 || (sec == 0 && usec < 0))
+ return 0;
+
+ ret = sec * 1000000ULL + usec;
+
+ return ret;
}
+
+uint64_t utime_since_now(const struct timeval *s)
+{
+ struct timeval t;
+
+ fio_gettime(&t, NULL);
+ return utime_since(s, &t);
+}
+
+uint64_t mtime_since(const struct timeval *s, const struct timeval *e)
+{
+ long sec, usec, ret;
+
+ sec = e->tv_sec - s->tv_sec;
+ usec = e->tv_usec - s->tv_usec;
+ if (sec > 0 && usec < 0) {
+ sec--;
+ usec += 1000000;
+ }
+
+ if (sec < 0 || (sec == 0 && usec < 0))
+ return 0;
+
+ sec *= 1000UL;
+ usec /= 1000UL;
+ ret = sec + usec;
+
+ return ret;
+}
+
+uint64_t mtime_since_now(const struct timeval *s)
+{
+ struct timeval t;
+ void *p = __builtin_return_address(0);
+
+ fio_gettime(&t, p);
+ return mtime_since(s, &t);
+}
+
+uint64_t time_since_now(const struct timeval *s)
+{
+ return mtime_since_now(s) / 1000;
+}
+
+#if defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK) && \
+ defined(CONFIG_SFAA)
+
+#define CLOCK_ENTRIES_DEBUG 100000
+#define CLOCK_ENTRIES_TEST 10000
+
+struct clock_entry {
+ uint32_t seq;
+ uint32_t cpu;
+ uint64_t tsc;
+};
+
+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;
+};
+
+static inline uint32_t atomic32_inc_return(uint32_t *seq)
+{
+ return 1 + __sync_fetch_and_add(seq, 1);
+}
+
+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;
+ int i;
+
+ memset(&cpu_mask, 0, sizeof(cpu_mask));
+ fio_cpu_set(&cpu_mask, t->cpu);
+
+ if (fio_setaffinity(gettid(), cpu_mask) == -1) {
+ log_err("clock setaffinity failed\n");
+ return (void *) 1;
+ }
+
+ pthread_mutex_lock(&t->lock);
+ pthread_mutex_unlock(&t->started);
+
+ last_seq = 0;
+ c = &t->entries[0];
+ for (i = 0; i < t->nr_entries; i++, c++) {
+ uint32_t seq;
+ uint64_t tsc;
+
+ c->cpu = t->cpu;
+ do {
+ seq = atomic32_inc_return(t->seq);
+ if (seq < last_seq)
+ break;
+ tsc = get_cpu_clock();
+ } while (seq != *t->seq);
+
+ c->seq = seq;
+ c->tsc = 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\n", t->cpu, clocks);
+ }
+
+ /*
+ * 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;
+
+ return NULL;
+}
+
+static int clock_cmp(const void *p1, const void *p2)
+{
+ const struct clock_entry *c1 = p1;
+ const struct clock_entry *c2 = p2;
+
+ if (c1->seq == c2->seq)
+ log_err("cs: bug in atomic sequence!\n");
+
+ return c1->seq - c2->seq;
+}
+
+int fio_monotonic_clocktest(int debug)
+{
+ struct clock_thread *cthreads;
+ unsigned int nr_cpus = cpus_online();
+ struct clock_entry *entries;
+ unsigned long nr_entries, tentries, failed = 0;
+ struct clock_entry *prev, *this;
+ uint32_t seq = 0;
+ unsigned int i;
+
+ if (debug) {
+ log_info("cs: reliable_tsc: %s\n", tsc_reliable ? "yes" : "no");
+
+#ifdef FIO_INC_DEBUG
+ 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);
+#endif
+ }
+
+ cthreads = malloc(nr_cpus * sizeof(struct clock_thread));
+ tentries = nr_entries * nr_cpus;
+ entries = malloc(tentries * sizeof(struct clock_entry));
+
+ 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->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);
+ if (pthread_create(&t->thread, NULL, clock_thread_fn, t)) {
+ failed++;
+ nr_cpus = i;
+ break;
+ }
+ }
+
+ 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);
+ }
+
+ for (i = 0; i < nr_cpus; i++) {
+ struct clock_thread *t = &cthreads[i];
+ void *ret;
+
+ pthread_join(t->thread, &ret);
+ if (ret)
+ failed++;
+ }
+ free(cthreads);
+
+ if (failed) {
+ if (debug)
+ log_err("Clocksource test: %lu threads failed\n", failed);
+ goto err;
+ }
+
+ qsort(entries, tentries, sizeof(struct clock_entry), clock_cmp);
+
+ for (failed = i = 0; i < tentries; i++) {
+ this = &entries[i];
+
+ if (!i) {
+ prev = this;
+ continue;
+ }
+
+ 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);
+ log_info("\t CPU%3u: TSC=%llu, SEQ=%u\n", this->cpu, (unsigned long long) this->tsc, this->seq);
+ failed++;
+ }
+
+ prev = this;
+ }
+
+ if (debug) {
+ if (failed)
+ log_info("cs: Failed: %lu\n", failed);
+ else
+ log_info("cs: Pass!\n");
+ }
+err:
+ free(entries);
+ return !!failed;
+}
+
+#else /* defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK) */
+
+int fio_monotonic_clocktest(int debug)
+{
+ if (debug)
+ log_info("cs: current platform does not support CPU clocks\n");
+ return 1;
+}
+
+#endif
projects / fio.git / blobdiff