Em Thu, Dec 29, 2016 at 11:13:39AM -0500, Waiman Long escreveu:
> This microbenchmark simulates how the use of different futex types
> can affect the actual performanace of userspace mutex locks. The
> usage is:
>
> perf bench futex mutex <options>
Showing the tool output is preferred, trim it if needed or state why
that is not possible.
> Three sets of simple mutex lock and unlock functions are implemented
> using the wait-wake, PI and TP futexes respectively. This
> microbenchmark then runs the locking rate measurement tests using
> either one of those mutexes or all of them consecutively.
>
> Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
> ---
> tools/perf/bench/Build | 1 +
> tools/perf/bench/bench.h | 1 +
> tools/perf/bench/futex-locks.c | 844 +++++++++++++++++++++++++++++++++++++++++
> tools/perf/bench/futex.h | 23 ++
> tools/perf/builtin-bench.c | 10 +
> tools/perf/check-headers.sh | 4 +
You forgot to document it in tools/perf/Documentation/perf-bench.txt
Also I would suggest you submit this first without supportint TP
futexes, i.e. supporting just what is in the kernel already, this way I
could cherry-pick this, which would be useful already for benchmarking
the existing types of futexes.
Then, after the new futex type is accepted into the kernel, in a
separate patch you would add support for it in 'perf bench futex mutex'.
Thanks,
- Arnaldo
> 6 files changed, 883 insertions(+)
> create mode 100644 tools/perf/bench/futex-locks.c
>
> diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
> index 60bf119..7ce1cd7 100644
> --- a/tools/perf/bench/Build
> +++ b/tools/perf/bench/Build
> @@ -6,6 +6,7 @@ perf-y += futex-wake.o
> perf-y += futex-wake-parallel.o
> perf-y += futex-requeue.o
> perf-y += futex-lock-pi.o
> +perf-y += futex-locks.o
>
> perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
> perf-$(CONFIG_X86_64) += mem-memset-x86-64-asm.o
> diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
> index 579a592..b0632df 100644
> --- a/tools/perf/bench/bench.h
> +++ b/tools/perf/bench/bench.h
> @@ -36,6 +36,7 @@
> int bench_futex_requeue(int argc, const char **argv, const char *prefix);
> /* pi futexes */
> int bench_futex_lock_pi(int argc, const char **argv, const char *prefix);
> +int bench_futex_mutex(int argc, const char **argv, const char *prefix);
>
> #define BENCH_FORMAT_DEFAULT_STR "default"
> #define BENCH_FORMAT_DEFAULT 0
> diff --git a/tools/perf/bench/futex-locks.c b/tools/perf/bench/futex-locks.c
> new file mode 100644
> index 0000000..ec1e627
> --- /dev/null
> +++ b/tools/perf/bench/futex-locks.c
> @@ -0,0 +1,844 @@
> +/*
> + * Copyright (C) 2016 Waiman Long <longman@xxxxxxxxxx>
> + *
> + * This microbenchmark simulates how the use of different futex types can
> + * affect the actual performanace of userspace locking primitives like mutex.
> + *
> + * The raw throughput of the futex lock and unlock calls is not a good
> + * indication of actual throughput of the mutex code as it may not really
> + * need to call into the kernel. Therefore, 3 sets of simple mutex lock and
> + * unlock functions are written to implenment a mutex lock using the
> + * wait-wake, PI and TP futexes respectively. These functions serve as the
> + * basis for measuring the locking throughput.
> + */
> +
> +#include <pthread.h>
> +
> +#include <signal.h>
> +#include <string.h>
> +#include "../util/stat.h"
> +#include "../perf-sys.h"
> +#include <subcmd/parse-options.h>
> +#include <linux/compiler.h>
> +#include <linux/kernel.h>
> +#include <errno.h>
> +#include "bench.h"
> +#include "futex.h"
> +
> +#include <err.h>
> +#include <stdlib.h>
> +#include <sys/time.h>
> +
> +#define CACHELINE_SIZE 64
> +#define gettid() syscall(SYS_gettid)
> +#define __cacheline_aligned __attribute__((__aligned__(CACHELINE_SIZE)))
> +
> +typedef u32 futex_t;
> +typedef void (*lock_fn_t)(futex_t *futex, int tid);
> +typedef void (*unlock_fn_t)(futex_t *futex, int tid);
> +
> +/*
> + * Statistical count list
> + */
> +enum {
> + STAT_OPS, /* # of exclusive locking operations */
> + STAT_LOCKS, /* # of exclusive lock futex calls */
> + STAT_UNLOCKS, /* # of exclusive unlock futex calls */
> + STAT_SLEEPS, /* # of exclusive lock sleeps */
> + STAT_EAGAINS, /* # of EAGAIN errors */
> + STAT_WAKEUPS, /* # of wakeups (unlock return) */
> + STAT_HANDOFFS, /* # of lock handoff (TP only) */
> + STAT_STEALS, /* # of lock steals (TP only) */
> + STAT_LOCKERRS, /* # of exclusive lock errors */
> + STAT_UNLKERRS, /* # of exclusive unlock errors */
> + STAT_NUM /* Total # of statistical count */
> +};
> +
> +/*
> + * Syscall time list
> + */
> +enum {
> + TIME_LOCK, /* Total exclusive lock syscall time */
> + TIME_UNLK, /* Total exclusive unlock syscall time */
> + TIME_NUM,
> +};
> +
> +struct worker {
> + futex_t *futex;
> + pthread_t thread;
> +
> + /*
> + * Per-thread operation statistics
> + */
> + u32 stats[STAT_NUM];
> +
> + /*
> + * Lock/unlock times
> + */
> + u64 times[TIME_NUM];
> +} __cacheline_aligned;
> +
> +/*
> + * Global cache-aligned futex
> + */
> +static futex_t __cacheline_aligned global_futex;
> +static futex_t *pfutex = &global_futex;
> +
> +static __thread futex_t thread_id; /* Thread ID */
> +static __thread int counter; /* Sleep counter */
> +
> +static struct worker *worker, *worker_alloc;
> +static unsigned int nsecs = 10;
> +static bool verbose, done, fshared, exit_now, timestat;
> +static unsigned int ncpus, nthreads;
> +static int flags;
> +static const char *ftype;
> +static int loadlat = 1;
> +static int locklat = 1;
> +static int wratio;
> +struct timeval start, end, runtime;
> +static unsigned int worker_start;
> +static unsigned int threads_starting;
> +static unsigned int threads_stopping;
> +static struct stats throughput_stats;
> +static lock_fn_t mutex_lock_fn;
> +static unlock_fn_t mutex_unlock_fn;
> +
> +/*
> + * Lock/unlock syscall time macro
> + */
> +static inline void systime_add(int tid, int item, struct timespec *begin,
> + struct timespec *_end)
> +{
> + worker[tid].times[item] += (_end->tv_sec - begin->tv_sec)*1000000000 +
> + _end->tv_nsec - begin->tv_nsec;
> +}
> +
> +static inline double stat_percent(struct worker *w, int top, int bottom)
> +{
> + return (double)w->stats[top] * 100 / w->stats[bottom];
> +}
> +
> +/*
> + * Inline functions to update the statistical counts
> + *
> + * Enable statistics collection may sometimes impact the locking rates
> + * to be measured. So we can specify the DISABLE_STAT macro to disable
> + * statistic counts collection for all except the core locking rate counts.
> + *
> + * #define DISABLE_STAT
> + */
> +#ifndef DISABLE_STAT
> +static inline void stat_add(int tid, int item, int num)
> +{
> + worker[tid].stats[item] += num;
> +}
> +
> +static inline void stat_inc(int tid, int item)
> +{
> + stat_add(tid, item, 1);
> +}
> +#else
> +static inline void stat_add(int tid __maybe_unused, int item __maybe_unused,
> + int num __maybe_unused)
> +{
> +}
> +
> +static inline void stat_inc(int tid __maybe_unused, int item __maybe_unused)
> +{
> +}
> +#endif
> +
> +/*
> + * The latency value within a lock critical section (load) and between locking
> + * operations is in term of the number of cpu_relax() calls that are being
> + * issued.
> + */
> +static const struct option mutex_options[] = {
> + OPT_INTEGER ('d', "locklat", &locklat, "Specify inter-locking latency (default = 1)"),
> + OPT_STRING ('f', "ftype", &ftype, "type", "Specify futex type: WW, PI, TP, all (default)"),
> + OPT_INTEGER ('L', "loadlat", &loadlat, "Specify load latency (default = 1)"),
> + OPT_UINTEGER('r', "runtime", &nsecs, "Specify runtime (in seconds, default = 10s)"),
> + OPT_BOOLEAN ('S', "shared", &fshared, "Use shared futexes instead of private ones"),
> + OPT_BOOLEAN ('T', "timestat", ×tat, "Track lock/unlock syscall times"),
> + OPT_UINTEGER('t', "threads", &nthreads, "Specify number of threads, default = # of CPUs"),
> + OPT_BOOLEAN ('v', "verbose", &verbose, "Verbose mode: display thread-level details"),
> + OPT_INTEGER ('w', "wait-ratio", &wratio, "Specify <n>/1024 of load is 1us sleep, default = 0"),
> + OPT_END()
> +};
> +
> +static const char * const bench_futex_mutex_usage[] = {
> + "perf bench futex mutex <options>",
> + NULL
> +};
> +
> +/**
> + * futex_cmpxchg() - atomic compare and exchange
> + * @uaddr: The address of the futex to be modified
> + * @oldval: The expected value of the futex
> + * @newval: The new value to try and assign to the futex
> + *
> + * Implement cmpxchg using gcc atomic builtins.
> + *
> + * Return: the old futex value.
> + */
> +static inline futex_t futex_cmpxchg(futex_t *uaddr, futex_t old, futex_t new)
> +{
> + return __sync_val_compare_and_swap(uaddr, old, new);
> +}
> +
> +/**
> + * futex_xchg() - atomic exchange
> + * @uaddr: The address of the futex to be modified
> + * @newval: The new value to assign to the futex
> + *
> + * Implement cmpxchg using gcc atomic builtins.
> + *
> + * Return: the old futex value.
> + */
> +static inline futex_t futex_xchg(futex_t *uaddr, futex_t new)
> +{
> + return __sync_lock_test_and_set(uaddr, new);
> +}
> +
> +/**
> + * atomic_dec_return - atomically decrement & return the new value
> + * @uaddr: The address of the futex to be decremented
> + * Return: The new value
> + */
> +static inline int atomic_dec_return(futex_t *uaddr)
> +{
> + return __sync_sub_and_fetch(uaddr, 1);
> +}
> +
> +/**
> + * atomic_inc_return - atomically increment & return the new value
> + * @uaddr: The address of the futex to be incremented
> + * Return: The new value
> + */
> +static inline int atomic_inc_return(futex_t *uaddr)
> +{
> + return __sync_add_and_fetch(uaddr, 1);
> +}
> +
> +/**********************[ MUTEX lock/unlock functions ]*********************/
> +
> +/*
> + * Wait-wake futex lock/unlock functions (Glibc implementation)
> + * futex value: 0 - unlocked
> + * 1 - locked
> + * 2 - locked with waiters (contended)
> + */
> +static void ww_mutex_lock(futex_t *futex, int tid)
> +{
> + struct timespec stime, etime;
> + futex_t val = *futex;
> + int ret;
> +
> + if (!val) {
> + val = futex_cmpxchg(futex, 0, 1);
> + if (val == 0)
> + return;
> + }
> +
> + for (;;) {
> + if (val != 2) {
> + /*
> + * Force value to 2 to indicate waiter
> + */
> + val = futex_xchg(futex, 2);
> + if (val == 0)
> + return;
> + }
> + if (timestat) {
> + clock_gettime(CLOCK_REALTIME, &stime);
> + ret = futex_wait(futex, 2, NULL, flags);
> + clock_gettime(CLOCK_REALTIME, &etime);
> + systime_add(tid, TIME_LOCK, &stime, &etime);
> + } else {
> + ret = futex_wait(futex, 2, NULL, flags);
> + }
> +
> + stat_inc(tid, STAT_LOCKS);
> + if (ret < 0) {
> + if (errno == EAGAIN)
> + stat_inc(tid, STAT_EAGAINS);
> + else
> + stat_inc(tid, STAT_LOCKERRS);
> + }
> +
> + val = *futex;
> + }
> +}
> +
> +static void ww_mutex_unlock(futex_t *futex, int tid)
> +{
> + struct timespec stime, etime;
> + futex_t val;
> + int ret;
> +
> + val = futex_xchg(futex, 0);
> +
> + if (val == 2) {
> + stat_inc(tid, STAT_UNLOCKS);
> + if (timestat) {
> + clock_gettime(CLOCK_REALTIME, &stime);
> + ret = futex_wake(futex, 1, flags);
> + clock_gettime(CLOCK_REALTIME, &etime);
> + systime_add(tid, TIME_UNLK, &stime, &etime);
> + } else {
> + ret = futex_wake(futex, 1, flags);
> + }
> + if (ret < 0)
> + stat_inc(tid, STAT_UNLKERRS);
> + else
> + stat_add(tid, STAT_WAKEUPS, ret);
> + }
> +}
> +
> +/*
> + * Alternate wait-wake futex lock/unlock functions with thread_id lock word
> + */
> +static void ww2_mutex_lock(futex_t *futex, int tid)
> +{
> + struct timespec stime, etime;
> + futex_t val = *futex;
> + int ret;
> +
> + if (!val) {
> + val = futex_cmpxchg(futex, 0, thread_id);
> + if (val == 0)
> + return;
> + }
> +
> + for (;;) {
> + /*
> + * Set the FUTEX_WAITERS bit, if not set yet.
> + */
> + while (!(val & FUTEX_WAITERS)) {
> + futex_t old;
> +
> + if (!val) {
> + val = futex_cmpxchg(futex, 0, thread_id);
> + if (val == 0)
> + return;
> + continue;
> + }
> + old = futex_cmpxchg(futex, val, val | FUTEX_WAITERS);
> + if (old == val) {
> + val |= FUTEX_WAITERS;
> + break;
> + }
> + val = old;
> + }
> + if (timestat) {
> + clock_gettime(CLOCK_REALTIME, &stime);
> + ret = futex_wait(futex, val, NULL, flags);
> + clock_gettime(CLOCK_REALTIME, &etime);
> + systime_add(tid, TIME_LOCK, &stime, &etime);
> + } else {
> + ret = futex_wait(futex, val, NULL, flags);
> + }
> + stat_inc(tid, STAT_LOCKS);
> + if (ret < 0) {
> + if (errno == EAGAIN)
> + stat_inc(tid, STAT_EAGAINS);
> + else
> + stat_inc(tid, STAT_LOCKERRS);
> + }
> +
> + val = *futex;
> + }
> +}
> +
> +static void ww2_mutex_unlock(futex_t *futex, int tid)
> +{
> + struct timespec stime, etime;
> + futex_t val;
> + int ret;
> +
> + val = futex_xchg(futex, 0);
> +
> + if ((val & FUTEX_TID_MASK) != thread_id)
> + stat_inc(tid, STAT_UNLKERRS);
> +
> + if (val & FUTEX_WAITERS) {
> + stat_inc(tid, STAT_UNLOCKS);
> + if (timestat) {
> + clock_gettime(CLOCK_REALTIME, &stime);
> + ret = futex_wake(futex, 1, flags);
> + clock_gettime(CLOCK_REALTIME, &etime);
> + systime_add(tid, TIME_UNLK, &stime, &etime);
> + } else {
> + ret = futex_wake(futex, 1, flags);
> + }
> + if (ret < 0)
> + stat_inc(tid, STAT_UNLKERRS);
> + else
> + stat_add(tid, STAT_WAKEUPS, ret);
> + }
> +}
> +
> +/*
> + * PI futex lock/unlock functions
> + */
> +static void pi_mutex_lock(futex_t *futex, int tid)
> +{
> + struct timespec stime, etime;
> + futex_t val;
> + int ret;
> +
> + val = futex_cmpxchg(futex, 0, thread_id);
> + if (val == 0)
> + return;
> +
> + /*
> + * Retry if an error happens
> + */
> + for (;;) {
> + if (timestat) {
> + clock_gettime(CLOCK_REALTIME, &stime);
> + ret = futex_lock_pi(futex, NULL, flags);
> + clock_gettime(CLOCK_REALTIME, &etime);
> + systime_add(tid, TIME_LOCK, &stime, &etime);
> + } else {
> + ret = futex_lock_pi(futex, NULL, flags);
> + }
> + stat_inc(tid, STAT_LOCKS);
> + if (ret >= 0)
> + break;
> + stat_inc(tid, STAT_LOCKERRS);
> + }
> +}
> +
> +static void pi_mutex_unlock(futex_t *futex, int tid)
> +{
> + struct timespec stime, etime;
> + futex_t val;
> + int ret;
> +
> + val = futex_cmpxchg(futex, thread_id, 0);
> + if (val == thread_id)
> + return;
> +
> + if (timestat) {
> + clock_gettime(CLOCK_REALTIME, &stime);
> + ret = futex_unlock_pi(futex, flags);
> + clock_gettime(CLOCK_REALTIME, &etime);
> + systime_add(tid, TIME_UNLK, &stime, &etime);
> + } else {
> + ret = futex_unlock_pi(futex, flags);
> + }
> + if (ret < 0)
> + stat_inc(tid, STAT_UNLKERRS);
> + else
> + stat_add(tid, STAT_WAKEUPS, ret);
> + stat_inc(tid, STAT_UNLOCKS);
> +}
> +
> +/*
> + * TP futex lock/unlock functions
> + */
> +static void tp_mutex_lock(futex_t *futex, int tid)
> +{
> + struct timespec stime, etime;
> + futex_t val;
> + int ret;
> +
> + val = futex_cmpxchg(futex, 0, thread_id);
> + if (val == 0)
> + return;
> +
> + /*
> + * Retry if an error happens
> + */
> + for (;;) {
> + if (timestat) {
> + clock_gettime(CLOCK_REALTIME, &stime);
> + ret = futex_lock(futex, NULL, flags);
> + clock_gettime(CLOCK_REALTIME, &etime);
> + systime_add(tid, TIME_LOCK, &stime, &etime);
> + } else {
> + ret = futex_lock(futex, NULL, flags);
> + }
> + stat_inc(tid, STAT_LOCKS);
> + if (ret >= 0)
> + break;
> + stat_inc(tid, STAT_LOCKERRS);
> + }
> + /*
> + * Get # of sleeps & locking method
> + */
> + stat_add(tid, STAT_SLEEPS, ret >> 16);
> + ret &= 0xff;
> + if (!ret)
> + stat_inc(tid, STAT_STEALS);
> + else if (ret == 2)
> + stat_inc(tid, STAT_HANDOFFS);
> +}
> +
> +static void tp_mutex_unlock(futex_t *futex, int tid)
> +{
> + struct timespec stime, etime;
> + futex_t val;
> + int ret;
> +
> + val = futex_cmpxchg(futex, thread_id, 0);
> + if (val == thread_id)
> + return;
> +
> + if (timestat) {
> + clock_gettime(CLOCK_REALTIME, &stime);
> + ret = futex_unlock(futex, flags);
> + clock_gettime(CLOCK_REALTIME, &etime);
> + systime_add(tid, TIME_UNLK, &stime, &etime);
> + } else {
> + ret = futex_unlock(futex, flags);
> + }
> + stat_inc(tid, STAT_UNLOCKS);
> + if (ret < 0)
> + stat_inc(tid, STAT_UNLKERRS);
> + else
> + stat_add(tid, STAT_WAKEUPS, ret);
> +}
> +
> +/**************************************************************************/
> +
> +/*
> + * Load function
> + */
> +static inline void load(int tid)
> +{
> + int n = loadlat;
> +
> + /*
> + * Optionally does a 1us sleep instead if wratio is defined and
> + * is within bound.
> + */
> + if (wratio && (((counter++ + tid) & 0x3ff) < wratio)) {
> + usleep(1);
> + return;
> + }
> +
> + while (n-- > 0)
> + cpu_relax();
> +}
> +
> +static inline void csdelay(void)
> +{
> + int n = locklat;
> +
> + while (n-- > 0)
> + cpu_relax();
> +}
> +
> +static void toggle_done(int sig __maybe_unused,
> + siginfo_t *info __maybe_unused,
> + void *uc __maybe_unused)
> +{
> + /* inform all threads that we're done for the day */
> + done = true;
> + gettimeofday(&end, NULL);
> + timersub(&end, &start, &runtime);
> + if (sig)
> + exit_now = true;
> +}
> +
> +static void *mutex_workerfn(void *arg)
> +{
> + long tid = (long)arg;
> + struct worker *w = &worker[tid];
> + lock_fn_t lock_fn = mutex_lock_fn;
> + unlock_fn_t unlock_fn = mutex_unlock_fn;
> +
> + thread_id = gettid();
> + counter = 0;
> +
> + atomic_dec_return(&threads_starting);
> +
> + /*
> + * Busy wait until asked to start
> + */
> + while (!worker_start)
> + cpu_relax();
> +
> + do {
> + lock_fn(w->futex, tid);
> + load(tid);
> + unlock_fn(w->futex, tid);
> + w->stats[STAT_OPS]++; /* One more locking operation */
> + csdelay();
> + } while (!done);
> +
> + if (verbose)
> + printf("[thread %3ld (%d)] exited.\n", tid, thread_id);
> + atomic_inc_return(&threads_stopping);
> + return NULL;
> +}
> +
> +static void create_threads(struct worker *w, pthread_attr_t *thread_attr,
> + void *(*workerfn)(void *arg), long tid)
> +{
> + cpu_set_t cpu;
> +
> + /*
> + * Bind each thread to a CPU
> + */
> + CPU_ZERO(&cpu);
> + CPU_SET(tid % ncpus, &cpu);
> + w->futex = pfutex;
> +
> + if (pthread_attr_setaffinity_np(thread_attr, sizeof(cpu_set_t), &cpu))
> + err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
> +
> + if (pthread_create(&w->thread, thread_attr, workerfn, (void *)tid))
> + err(EXIT_FAILURE, "pthread_create");
> +}
> +
> +static int futex_mutex_type(const char **ptype)
> +{
> + const char *type = *ptype;
> +
> + if (!strcasecmp(type, "WW")) {
> + *ptype = "WW";
> + mutex_lock_fn = ww_mutex_lock;
> + mutex_unlock_fn = ww_mutex_unlock;
> + } else if (!strcasecmp(type, "WW2")) {
> + *ptype = "WW2";
> + mutex_lock_fn = ww2_mutex_lock;
> + mutex_unlock_fn = ww2_mutex_unlock;
> + } else if (!strcasecmp(type, "PI")) {
> + *ptype = "PI";
> + mutex_lock_fn = pi_mutex_lock;
> + mutex_unlock_fn = pi_mutex_unlock;
> + } else if (!strcasecmp(type, "TP")) {
> + *ptype = "TP";
> + mutex_lock_fn = tp_mutex_lock;
> + mutex_unlock_fn = tp_mutex_unlock;
> +
> + /*
> + * Check if TP futex is supported.
> + */
> + futex_unlock(&global_futex, 0);
> + if (errno == ENOSYS) {
> + fprintf(stderr,
> + "\nTP futexes are not supported by the kernel!\n");
> + return -1;
> + }
> + } else {
> + return -1;
> + }
> + return 0;
> +}
> +
> +static void futex_test_driver(const char *futex_type,
> + int (*proc_type)(const char **ptype),
> + void *(*workerfn)(void *arg))
> +{
> + u64 us;
> + int i, j;
> + struct worker total;
> + double avg, stddev;
> + pthread_attr_t thread_attr;
> +
> + /*
> + * There is an extra blank line before the error counts to highlight
> + * them.
> + */
> + const char *desc[STAT_NUM] = {
> + [STAT_OPS] = "Total exclusive locking ops",
> + [STAT_LOCKS] = "Exclusive lock futex calls",
> + [STAT_UNLOCKS] = "Exclusive unlock futex calls",
> + [STAT_SLEEPS] = "Exclusive lock sleeps",
> + [STAT_WAKEUPS] = "Process wakeups",
> + [STAT_EAGAINS] = "EAGAIN lock errors",
> + [STAT_HANDOFFS] = "Lock handoffs",
> + [STAT_STEALS] = "Lock stealings",
> + [STAT_LOCKERRS] = "\nExclusive lock errors",
> + [STAT_UNLKERRS] = "\nExclusive unlock errors",
> + };
> +
> + if (exit_now)
> + return;
> +
> + if (proc_type(&futex_type) < 0) {
> + fprintf(stderr, "Unknown futex type '%s'!\n", futex_type);
> + exit(1);
> + }
> +
> + printf("\n=====================================\n");
> + printf("[PID %d]: %d threads doing %s futex lockings (load=%d) for %d secs.\n\n",
> + getpid(), nthreads, futex_type, loadlat, nsecs);
> +
> + init_stats(&throughput_stats);
> +
> + *pfutex = 0;
> + done = false;
> + threads_starting = nthreads;
> + pthread_attr_init(&thread_attr);
> +
> + for (i = 0; i < (int)nthreads; i++)
> + create_threads(&worker[i], &thread_attr, workerfn, i);
> +
> + while (threads_starting)
> + usleep(1);
> +
> + gettimeofday(&start, NULL);
> +
> + /*
> + * Start the test
> + *
> + * Unlike the other futex benchmarks, this one uses busy waiting
> + * instead of pthread APIs to make sure that all the threads (except
> + * the one that shares CPU with the parent) will start more or less
> + * simultaineously.
> + */
> + atomic_inc_return(&worker_start);
> + sleep(nsecs);
> + toggle_done(0, NULL, NULL);
> +
> + /*
> + * In verbose mode, we check if all the threads have been stopped
> + * after 1ms and report the status if some are still running.
> + */
> + if (verbose) {
> + usleep(1000);
> + if (threads_stopping != nthreads) {
> + printf("%d threads still running 1ms after timeout"
> + " - futex = 0x%x\n",
> + nthreads - threads_stopping, *pfutex);
> + /*
> + * If the threads are still running after 10s,
> + * go directly to statistics printing and exit.
> + */
> + for (i = 10; i > 0; i--) {
> + sleep(1);
> + if (threads_stopping == nthreads)
> + break;
> + }
> + if (!i) {
> + printf("*** Threads waiting ABORTED!! ***\n\n");
> + goto print_stat;
> + }
> + }
> + }
> +
> + for (i = 0; i < (int)nthreads; i++) {
> + int ret = pthread_join(worker[i].thread, NULL);
> +
> + if (ret)
> + err(EXIT_FAILURE, "pthread_join");
> + }
> +
> +print_stat:
> + pthread_attr_destroy(&thread_attr);
> +
> + us = runtime.tv_sec * 1000000 + runtime.tv_usec;
> + memset(&total, 0, sizeof(total));
> + for (i = 0; i < (int)nthreads; i++) {
> + /*
> + * Get a rounded estimate of the # of locking ops/sec.
> + */
> + u64 tp = (u64)worker[i].stats[STAT_OPS] * 1000000 / us;
> +
> + for (j = 0; j < STAT_NUM; j++)
> + total.stats[j] += worker[i].stats[j];
> +
> + update_stats(&throughput_stats, tp);
> + if (verbose)
> + printf("[thread %3d] futex: %p [ %'ld ops/sec ]\n",
> + i, worker[i].futex, (long)tp);
> + }
> +
> + avg = avg_stats(&throughput_stats);
> + stddev = stddev_stats(&throughput_stats);
> +
> + printf("Locking statistics:\n");
> + printf("%-28s = %'.2fs\n", "Test run time", (double)us/1000000);
> + for (i = 0; i < STAT_NUM; i++)
> + if (total.stats[i])
> + printf("%-28s = %'d\n", desc[i], total.stats[i]);
> +
> + if (timestat && total.times[TIME_LOCK]) {
> + printf("\nSyscall times:\n");
> + if (total.stats[STAT_LOCKS])
> + printf("Avg exclusive lock syscall = %'ldns\n",
> + total.times[TIME_LOCK]/total.stats[STAT_LOCKS]);
> + if (total.stats[STAT_UNLOCKS])
> + printf("Avg exclusive unlock syscall = %'ldns\n",
> + total.times[TIME_UNLK]/total.stats[STAT_UNLOCKS]);
> + }
> +
> + printf("\nPercentages:\n");
> + if (total.stats[STAT_LOCKS])
> + printf("Exclusive lock futex calls = %.1f%%\n",
> + stat_percent(&total, STAT_LOCKS, STAT_OPS));
> + if (total.stats[STAT_UNLOCKS])
> + printf("Exclusive unlock futex calls = %.1f%%\n",
> + stat_percent(&total, STAT_UNLOCKS, STAT_OPS));
> + if (total.stats[STAT_EAGAINS])
> + printf("EAGAIN lock errors = %.1f%%\n",
> + stat_percent(&total, STAT_EAGAINS, STAT_LOCKS));
> + if (total.stats[STAT_WAKEUPS])
> + printf("Process wakeups = %.1f%%\n",
> + stat_percent(&total, STAT_WAKEUPS, STAT_UNLOCKS));
> +
> + printf("\nPer-thread Locking Rates:\n");
> + printf("Avg = %'d ops/sec (+- %.2f%%)\n", (int)(avg + 0.5),
> + rel_stddev_stats(stddev, avg));
> + printf("Min = %'d ops/sec\n", (int)throughput_stats.min);
> + printf("Max = %'d ops/sec\n", (int)throughput_stats.max);
> +
> + if (*pfutex != 0)
> + printf("\nResidual futex value = 0x%x\n", *pfutex);
> +
> + /* Clear the workers area */
> + memset(worker, 0, sizeof(*worker) * nthreads);
> +}
> +
> +int bench_futex_mutex(int argc, const char **argv,
> + const char *prefix __maybe_unused)
> +{
> + struct sigaction act;
> +
> + argc = parse_options(argc, argv, mutex_options,
> + bench_futex_mutex_usage, 0);
> + if (argc)
> + goto err;
> +
> + ncpus = sysconf(_SC_NPROCESSORS_ONLN);
> +
> + sigfillset(&act.sa_mask);
> + act.sa_sigaction = toggle_done;
> + sigaction(SIGINT, &act, NULL);
> +
> + if (!nthreads)
> + nthreads = ncpus;
> +
> + /*
> + * Since the allocated memory buffer may not be properly cacheline
> + * aligned, we need to allocate one more than needed and manually
> + * adjust array boundary to be cacheline aligned.
> + */
> + worker_alloc = calloc(nthreads + 1, sizeof(*worker));
> + if (!worker_alloc)
> + err(EXIT_FAILURE, "calloc");
> + worker = (void *)((unsigned long)&worker_alloc[1] &
> + ~(CACHELINE_SIZE - 1));
> +
> + if (!fshared)
> + flags = FUTEX_PRIVATE_FLAG;
> +
> + if (!ftype || !strcmp(ftype, "all")) {
> + futex_test_driver("WW", futex_mutex_type, mutex_workerfn);
> + futex_test_driver("PI", futex_mutex_type, mutex_workerfn);
> + futex_test_driver("TP", futex_mutex_type, mutex_workerfn);
> + } else {
> + futex_test_driver(ftype, futex_mutex_type, mutex_workerfn);
> + }
> + free(worker_alloc);
> + return 0;
> +err:
> + usage_with_options(bench_futex_mutex_usage, mutex_options);
> + exit(EXIT_FAILURE);
> +}
> diff --git a/tools/perf/bench/futex.h b/tools/perf/bench/futex.h
> index ba7c735..be1eb7a 100644
> --- a/tools/perf/bench/futex.h
> +++ b/tools/perf/bench/futex.h
> @@ -87,6 +87,29 @@
> val, opflags);
> }
>
> +#ifndef FUTEX_LOCK
> +#define FUTEX_LOCK 0xff /* Disable the use of TP futexes */
> +#define FUTEX_UNLOCK 0xff
> +#endif /* FUTEX_LOCK */
> +
> +/**
> + * futex_lock() - lock the TP futex
> + */
> +static inline int
> +futex_lock(u_int32_t *uaddr, struct timespec *timeout, int opflags)
> +{
> + return futex(uaddr, FUTEX_LOCK, 0, timeout, NULL, 0, opflags);
> +}
> +
> +/**
> + * futex_unlock() - unlock the TP futex
> + */
> +static inline int
> +futex_unlock(u_int32_t *uaddr, int opflags)
> +{
> + return futex(uaddr, FUTEX_UNLOCK, 0, NULL, NULL, 0, opflags);
> +}
> +
> #ifndef HAVE_PTHREAD_ATTR_SETAFFINITY_NP
> #include <pthread.h>
> static inline int pthread_attr_setaffinity_np(pthread_attr_t *attr,
> diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
> index a1cddc6..bf4418d 100644
> --- a/tools/perf/builtin-bench.c
> +++ b/tools/perf/builtin-bench.c
> @@ -20,6 +20,7 @@
> #include "builtin.h"
> #include "bench/bench.h"
>
> +#include <locale.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> @@ -62,6 +63,7 @@ struct bench {
> { "requeue", "Benchmark for futex requeue calls", bench_futex_requeue },
> /* pi-futexes */
> { "lock-pi", "Benchmark for futex lock_pi calls", bench_futex_lock_pi },
> + { "mutex", "Benchmark for mutex locks using futexes", bench_futex_mutex },
> { "all", "Run all futex benchmarks", NULL },
> { NULL, NULL, NULL }
> };
> @@ -215,6 +217,7 @@ int cmd_bench(int argc, const char **argv, const char *prefix __maybe_unused)
> {
> struct collection *coll;
> int ret = 0;
> + char *locale;
>
> if (argc < 2) {
> /* No collection specified. */
> @@ -222,6 +225,13 @@ int cmd_bench(int argc, const char **argv, const char *prefix __maybe_unused)
> goto end;
> }
>
> + /*
> + * Enable better number formatting.
> + */
> + locale = setlocale(LC_NUMERIC, "");
> + if (!strcmp(locale, "C"))
> + setlocale(LC_NUMERIC, "en_US");
> +
> argc = parse_options(argc, argv, bench_options, bench_usage,
> PARSE_OPT_STOP_AT_NON_OPTION);
>
> diff --git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh
> index c747bfd..6ec5f2d 100755
> --- a/tools/perf/check-headers.sh
> +++ b/tools/perf/check-headers.sh
> @@ -57,3 +57,7 @@ check arch/x86/lib/memcpy_64.S -B -I "^EXPORT_SYMBOL" -I "^#include <asm/
> check arch/x86/lib/memset_64.S -B -I "^EXPORT_SYMBOL" -I "^#include <asm/export.h>"
> check include/uapi/asm-generic/mman.h -B -I "^#include <\(uapi/\)*asm-generic/mman-common.h>"
> check include/uapi/linux/mman.h -B -I "^#include <\(uapi/\)*asm/mman.h>"
> +
> +# need to link to the latest futex.h header
> +[[ -f ../../include/uapi/linux/futex.h ]] &&
> + ln -sf ../../../../../include/uapi/linux/futex.h util/include/linux
> --
> 1.8.3.1
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