by tip-bot for Vasyl Gomonovych

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Subject: [tip:perf/core] perf bench: Add epoll parallel epoll_wait benchmark

Commit-ID: 121dd9ea0116de3e79a4903a84018190c595e2b6
Gitweb: https://git.kernel.org/tip/121dd9ea0116de3e79a4903a84018190c595e2b6
Author: Davidlohr Bueso <[email protected]>
AuthorDate: Tue, 6 Nov 2018 07:22:25 -0800
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Wed, 21 Nov 2018 22:38:47 -0300

perf bench: Add epoll parallel epoll_wait benchmark

This program benchmarks concurrent epoll_wait(2) for file descriptors
that are monitored with with EPOLLIN along various semantics, by a
single epoll instance. Such conditions can be found when using
single/combined or multiple queuing when load balancing.

Each thread has a number of private, nonblocking file descriptors,
referred to as fdmap. A writer thread will constantly be writing to the
fdmaps of all threads, minimizing each threads's chances of epoll_wait
not finding any ready read events and blocking as this is not what we
want to stress. Full details in the start of the C file.

Committer testing:

# perf bench
Usage:
perf bench [<common options>] <collection> <benchmark> [<options>]

# List of all available benchmark collections:

sched: Scheduler and IPC benchmarks
mem: Memory access benchmarks
numa: NUMA scheduling and MM benchmarks
futex: Futex stressing benchmarks
epoll: Epoll stressing benchmarks
all: All benchmarks

# perf bench epoll

# List of available benchmarks for collection 'epoll':

wait: Benchmark epoll concurrent epoll_waits
all: Run all futex benchmarks

# perf bench epoll wait
# Running 'epoll/wait' benchmark:
Run summary [PID 19295]: 3 threads monitoring on 64 file-descriptors for 8 secs.

[thread 0] fdmap: 0xdaa650 ... 0xdaa74c [ 328241 ops/sec ]
[thread 1] fdmap: 0xdaa900 ... 0xdaa9fc [ 351695 ops/sec ]
[thread 2] fdmap: 0xdaabb0 ... 0xdaacac [ 381423 ops/sec ]

Averaged 353786 operations/sec (+- 4.35%), total secs = 8
#

Committer notes:

Fix the build on debian:experimental-x-mips, debian:experimental-x-mipsel
and others:

CC /tmp/build/perf/bench/epoll-wait.o
bench/epoll-wait.c: In function 'writerfn':
bench/epoll-wait.c:399:12: error: format '%ld' expects argument of type 'long int', but argument 2 has type 'size_t' {aka 'unsigned int'} [-Werror=format=]
printinfo("exiting writer-thread (total full-loops: %ld)\n", iter);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~
bench/epoll-wait.c:86:31: note: in definition of macro 'printinfo'
do { if (__verbose) { printf(fmt, ## arg); fflush(stdout); } } while (0)
^~~
cc1: all warnings being treated as errors

Signed-off-by: Davidlohr Bueso <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Jason Baron <[email protected]> <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/20181106182349.thdkpvshkna5vd7o@linux-r8p5>
[ Applied above fixup as per Davidlohr's request ]
[ Use inttypes.h to print rlim_t fields, fixing the build on Alpine Linux / musl libc ]
[ Check if eventfd() is available, i.e. if HAVE_EVENTFD is defined ]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/Documentation/perf-bench.txt | 7 +
tools/perf/bench/Build | 2 +
tools/perf/bench/bench.h | 2 +
tools/perf/bench/epoll-wait.c | 540 ++++++++++++++++++++++++++++++++
tools/perf/builtin-bench.c | 12 +
5 files changed, 563 insertions(+)

diff --git a/tools/perf/Documentation/perf-bench.txt b/tools/perf/Documentation/perf-bench.txt
index 34750fc32714..3a6b2e73b2e8 100644
--- a/tools/perf/Documentation/perf-bench.txt
+++ b/tools/perf/Documentation/perf-bench.txt
@@ -58,6 +58,9 @@ SUBSYSTEM
'futex'::
Futex stressing benchmarks.

+'epoll'::
+ Eventpoll (epoll) stressing benchmarks.
+
'all'::
All benchmark subsystems.

@@ -203,6 +206,10 @@ Suite for evaluating requeue calls.
*lock-pi*::
Suite for evaluating futex lock_pi calls.

+SUITES FOR 'epoll'
+~~~~~~~~~~~~~~~~~~
+*wait*::
+Suite for evaluating concurrent epoll_wait calls.

SEE ALSO
--------
diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index eafce1a130a1..2bb79b542d53 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -7,6 +7,8 @@ perf-y += futex-wake-parallel.o
perf-y += futex-requeue.o
perf-y += futex-lock-pi.o

+perf-y += epoll-wait.o
+
perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
perf-$(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 8299c76046cd..6e1f091ced96 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -38,6 +38,8 @@ int bench_futex_requeue(int argc, const char **argv);
/* pi futexes */
int bench_futex_lock_pi(int argc, const char **argv);

+int bench_epoll_wait(int argc, const char **argv);
+
#define BENCH_FORMAT_DEFAULT_STR "default"
#define BENCH_FORMAT_DEFAULT 0
#define BENCH_FORMAT_SIMPLE_STR "simple"
diff --git a/tools/perf/bench/epoll-wait.c b/tools/perf/bench/epoll-wait.c
new file mode 100644
index 000000000000..5a11534e96a0
--- /dev/null
+++ b/tools/perf/bench/epoll-wait.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifdef HAVE_EVENTFD
+/*
+ * Copyright (C) 2018 Davidlohr Bueso.
+ *
+ * This program benchmarks concurrent epoll_wait(2) monitoring multiple
+ * file descriptors under one or two load balancing models. The first,
+ * and default, is the single/combined queueing (which refers to a single
+ * epoll instance for N worker threads):
+ *
+ * |---> [worker A]
+ * |---> [worker B]
+ * [combined queue] .---> [worker C]
+ * |---> [worker D]
+ * |---> [worker E]
+ *
+ * While the second model, enabled via --multiq option, uses multiple
+ * queueing (which refers to one epoll instance per worker). For example,
+ * short lived tcp connections in a high throughput httpd server will
+ * ditribute the accept()'ing connections across CPUs. In this case each
+ * worker does a limited amount of processing.
+ *
+ * [queue A] ---> [worker]
+ * [queue B] ---> [worker]
+ * [queue C] ---> [worker]
+ * [queue D] ---> [worker]
+ * [queue E] ---> [worker]
+ *
+ * Naturally, the single queue will enforce more concurrency on the epoll
+ * instance, and can therefore scale poorly compared to multiple queues.
+ * However, this is a benchmark raw data and must be taken with a grain of
+ * salt when choosing how to make use of sys_epoll.
+
+ * Each thread has a number of private, nonblocking file descriptors,
+ * referred to as fdmap. A writer thread will constantly be writing to
+ * the fdmaps of all threads, minimizing each threads's chances of
+ * epoll_wait not finding any ready read events and blocking as this
+ * is not what we want to stress. The size of the fdmap can be adjusted
+ * by the user; enlarging the value will increase the chances of
+ * epoll_wait(2) blocking as the lineal writer thread will take "longer",
+ * at least at a high level.
+ *
+ * Note that because fds are private to each thread, this workload does
+ * not stress scenarios where multiple tasks are awoken per ready IO; ie:
+ * EPOLLEXCLUSIVE semantics.
+ *
+ * The end result/metric is throughput: number of ops/second where an
+ * operation consists of:
+ *
+ * epoll_wait(2) + [others]
+ *
+ * ... where [others] is the cost of re-adding the fd (EPOLLET),
+ * or rearming it (EPOLLONESHOT).
+ *
+ *
+ * The purpose of this is program is that it be useful for measuring
+ * kernel related changes to the sys_epoll, and not comparing different
+ * IO polling methods, for example. Hence everything is very adhoc and
+ * outputs raw microbenchmark numbers. Also this uses eventfd, similar
+ * tools tend to use pipes or sockets, but the result is the same.
+ */
+
+/* For the CLR_() macros */
+#include <string.h>
+#include <pthread.h>
+
+#include <errno.h>
+#include <inttypes.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/epoll.h>
+#include <sys/eventfd.h>
+#include <sys/types.h>
+
+#include "../util/stat.h"
+#include <subcmd/parse-options.h>
+#include "bench.h"
+#include "cpumap.h"
+
+#include <err.h>
+
+#define printinfo(fmt, arg...) \
+ do { if (__verbose) { printf(fmt, ## arg); fflush(stdout); } } while (0)
+
+static unsigned int nthreads = 0;
+static unsigned int nsecs = 8;
+struct timeval start, end, runtime;
+static bool wdone, done, __verbose, randomize, nonblocking;
+
+/*
+ * epoll related shared variables.
+ */
+
+/* Maximum number of nesting allowed inside epoll sets */
+#define EPOLL_MAXNESTS 4
+
+static int epollfd;
+static int *epollfdp;
+static bool noaffinity;
+static unsigned int nested = 0;
+static bool et; /* edge-trigger */
+static bool oneshot;
+static bool multiq; /* use an epoll instance per thread */
+
+/* amount of fds to monitor, per thread */
+static unsigned int nfds = 64;
+
+static pthread_mutex_t thread_lock;
+static unsigned int threads_starting;
+static struct stats throughput_stats;
+static pthread_cond_t thread_parent, thread_worker;
+
+struct worker {
+ int tid;
+ int epollfd; /* for --multiq */
+ pthread_t thread;
+ unsigned long ops;
+ int *fdmap;
+};
+
+static const struct option options[] = {
+ /* general benchmark options */
+ OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"),
+ OPT_UINTEGER('r', "runtime", &nsecs, "Specify runtime (in seconds)"),
+ OPT_UINTEGER('f', "nfds", &nfds, "Specify amount of file descriptors to monitor for each thread"),
+ OPT_BOOLEAN( 'n', "noaffinity", &noaffinity, "Disables CPU affinity"),
+ OPT_BOOLEAN('R', "randomize", &randomize, "Enable random write behaviour (default is lineal)"),
+ OPT_BOOLEAN( 'v', "verbose", &__verbose, "Verbose mode"),
+
+ /* epoll specific options */
+ OPT_BOOLEAN( 'm', "multiq", &multiq, "Use multiple epoll instances (one per thread)"),
+ OPT_BOOLEAN( 'B', "nonblocking", &nonblocking, "Nonblocking epoll_wait(2) behaviour"),
+ OPT_UINTEGER( 'N', "nested", &nested, "Nesting level epoll hierarchy (default is 0, no nesting)"),
+ OPT_BOOLEAN( 'S', "oneshot", &oneshot, "Use EPOLLONESHOT semantics"),
+ OPT_BOOLEAN( 'E', "edge", &et, "Use Edge-triggered interface (default is LT)"),
+
+ OPT_END()
+};
+
+static const char * const bench_epoll_wait_usage[] = {
+ "perf bench epoll wait <options>",
+ NULL
+};
+
+
+/*
+ * Arrange the N elements of ARRAY in random order.
+ * Only effective if N is much smaller than RAND_MAX;
+ * if this may not be the case, use a better random
+ * number generator. -- Ben Pfaff.
+ */
+static void shuffle(void *array, size_t n, size_t size)
+{
+ char *carray = array;
+ void *aux;
+ size_t i;
+
+ if (n <= 1)
+ return;
+
+ aux = calloc(1, size);
+ if (!aux)
+ err(EXIT_FAILURE, "calloc");
+
+ for (i = 1; i < n; ++i) {
+ size_t j = i + rand() / (RAND_MAX / (n - i) + 1);
+ j *= size;
+
+ memcpy(aux, &carray[j], size);
+ memcpy(&carray[j], &carray[i*size], size);
+ memcpy(&carray[i*size], aux, size);
+ }
+
+ free(aux);
+}
+
+
+static void *workerfn(void *arg)
+{
+ int fd, ret, r;
+ struct worker *w = (struct worker *) arg;
+ unsigned long ops = w->ops;
+ struct epoll_event ev;
+ uint64_t val;
+ int to = nonblocking? 0 : -1;
+ int efd = multiq ? w->epollfd : epollfd;
+
+ pthread_mutex_lock(&thread_lock);
+ threads_starting--;
+ if (!threads_starting)
+ pthread_cond_signal(&thread_parent);
+ pthread_cond_wait(&thread_worker, &thread_lock);
+ pthread_mutex_unlock(&thread_lock);
+
+ do {
+ /*
+ * Block undefinitely waiting for the IN event.
+ * In order to stress the epoll_wait(2) syscall,
+ * call it event per event, instead of a larger
+ * batch (max)limit.
+ */
+ do {
+ ret = epoll_wait(efd, &ev, 1, to);
+ } while (ret < 0 && errno == EINTR);
+ if (ret < 0)
+ err(EXIT_FAILURE, "epoll_wait");
+
+ fd = ev.data.fd;
+
+ do {
+ r = read(fd, &val, sizeof(val));
+ } while (!done && (r < 0 && errno == EAGAIN));
+
+ if (et) {
+ ev.events = EPOLLIN | EPOLLET;
+ ret = epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ev);
+ }
+
+ if (oneshot) {
+ /* rearm the file descriptor with a new event mask */
+ ev.events |= EPOLLIN | EPOLLONESHOT;
+ ret = epoll_ctl(efd, EPOLL_CTL_MOD, fd, &ev);
+ }
+
+ ops++;
+ } while (!done);
+
+ if (multiq)
+ close(w->epollfd);
+
+ w->ops = ops;
+ return NULL;
+}
+
+static void nest_epollfd(struct worker *w)
+{
+ unsigned int i;
+ struct epoll_event ev;
+ int efd = multiq ? w->epollfd : epollfd;
+
+ if (nested > EPOLL_MAXNESTS)
+ nested = EPOLL_MAXNESTS;
+
+ epollfdp = calloc(nested, sizeof(*epollfdp));
+ if (!epollfdp)
+ err(EXIT_FAILURE, "calloc");
+
+ for (i = 0; i < nested; i++) {
+ epollfdp[i] = epoll_create(1);
+ if (epollfdp[i] < 0)
+ err(EXIT_FAILURE, "epoll_create");
+ }
+
+ ev.events = EPOLLHUP; /* anything */
+ ev.data.u64 = i; /* any number */
+
+ for (i = nested - 1; i; i--) {
+ if (epoll_ctl(epollfdp[i - 1], EPOLL_CTL_ADD,
+ epollfdp[i], &ev) < 0)
+ err(EXIT_FAILURE, "epoll_ctl");
+ }
+
+ if (epoll_ctl(efd, EPOLL_CTL_ADD, *epollfdp, &ev) < 0)
+ err(EXIT_FAILURE, "epoll_ctl");
+}
+
+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);
+}
+
+static void print_summary(void)
+{
+ unsigned long avg = avg_stats(&throughput_stats);
+ double stddev = stddev_stats(&throughput_stats);
+
+ printf("\nAveraged %ld operations/sec (+- %.2f%%), total secs = %d\n",
+ avg, rel_stddev_stats(stddev, avg),
+ (int) runtime.tv_sec);
+}
+
+static int do_threads(struct worker *worker, struct cpu_map *cpu)
+{
+ pthread_attr_t thread_attr, *attrp = NULL;
+ cpu_set_t cpuset;
+ unsigned int i, j;
+ int ret, events = EPOLLIN;
+
+ if (oneshot)
+ events |= EPOLLONESHOT;
+ if (et)
+ events |= EPOLLET;
+
+ printinfo("starting worker/consumer %sthreads%s\n",
+ noaffinity ? "":"CPU affinity ",
+ nonblocking ? " (nonblocking)":"");
+ if (!noaffinity)
+ pthread_attr_init(&thread_attr);
+
+ for (i = 0; i < nthreads; i++) {
+ struct worker *w = &worker[i];
+
+ if (multiq) {
+ w->epollfd = epoll_create(1);
+ if (w->epollfd < 0)
+ err(EXIT_FAILURE, "epoll_create");
+
+ if (nested)
+ nest_epollfd(w);
+ }
+
+ w->tid = i;
+ w->fdmap = calloc(nfds, sizeof(int));
+ if (!w->fdmap)
+ return 1;
+
+ for (j = 0; j < nfds; j++) {
+ int efd = multiq ? w->epollfd : epollfd;
+ struct epoll_event ev;
+
+ w->fdmap[j] = eventfd(0, EFD_NONBLOCK);
+ if (w->fdmap[j] < 0)
+ err(EXIT_FAILURE, "eventfd");
+
+ ev.data.fd = w->fdmap[j];
+ ev.events = events;
+
+ ret = epoll_ctl(efd, EPOLL_CTL_ADD,
+ w->fdmap[j], &ev);
+ if (ret < 0)
+ err(EXIT_FAILURE, "epoll_ctl");
+ }
+
+ if (!noaffinity) {
+ CPU_ZERO(&cpuset);
+ CPU_SET(cpu->map[i % cpu->nr], &cpuset);
+
+ ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset);
+ if (ret)
+ err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
+
+ attrp = &thread_attr;
+ }
+
+ ret = pthread_create(&w->thread, attrp, workerfn,
+ (void *)(struct worker *) w);
+ if (ret)
+ err(EXIT_FAILURE, "pthread_create");
+ }
+
+ if (!noaffinity)
+ pthread_attr_destroy(&thread_attr);
+
+ return ret;
+}
+
+static void *writerfn(void *p)
+{
+ struct worker *worker = p;
+ size_t i, j, iter;
+ const uint64_t val = 1;
+ ssize_t sz;
+ struct timespec ts = { .tv_sec = 0,
+ .tv_nsec = 500 };
+
+ printinfo("starting writer-thread: doing %s writes ...\n",
+ randomize? "random":"lineal");
+
+ for (iter = 0; !wdone; iter++) {
+ if (randomize) {
+ shuffle((void *)worker, nthreads, sizeof(*worker));
+ }
+
+ for (i = 0; i < nthreads; i++) {
+ struct worker *w = &worker[i];
+
+ if (randomize) {
+ shuffle((void *)w->fdmap, nfds, sizeof(int));
+ }
+
+ for (j = 0; j < nfds; j++) {
+ do {
+ sz = write(w->fdmap[j], &val, sizeof(val));
+ } while (!wdone && (sz < 0 && errno == EAGAIN));
+ }
+ }
+
+ nanosleep(&ts, NULL);
+ }
+
+ printinfo("exiting writer-thread (total full-loops: %zd)\n", iter);
+ return NULL;
+}
+
+static int cmpworker(const void *p1, const void *p2)
+{
+
+ struct worker *w1 = (struct worker *) p1;
+ struct worker *w2 = (struct worker *) p2;
+ return w1->tid > w2->tid;
+}
+
+int bench_epoll_wait(int argc, const char **argv)
+{
+ int ret = 0;
+ struct sigaction act;
+ unsigned int i;
+ struct worker *worker = NULL;
+ struct cpu_map *cpu;
+ pthread_t wthread;
+ struct rlimit rl, prevrl;
+
+ argc = parse_options(argc, argv, options, bench_epoll_wait_usage, 0);
+ if (argc) {
+ usage_with_options(bench_epoll_wait_usage, options);
+ exit(EXIT_FAILURE);
+ }
+
+ sigfillset(&act.sa_mask);
+ act.sa_sigaction = toggle_done;
+ sigaction(SIGINT, &act, NULL);
+
+ cpu = cpu_map__new(NULL);
+ if (!cpu)
+ goto errmem;
+
+ /* a single, main epoll instance */
+ if (!multiq) {
+ epollfd = epoll_create(1);
+ if (epollfd < 0)
+ err(EXIT_FAILURE, "epoll_create");
+
+ /*
+ * Deal with nested epolls, if any.
+ */
+ if (nested)
+ nest_epollfd(NULL);
+ }
+
+ printinfo("Using %s queue model\n", multiq ? "multi" : "single");
+ printinfo("Nesting level(s): %d\n", nested);
+
+ /* default to the number of CPUs and leave one for the writer pthread */
+ if (!nthreads)
+ nthreads = cpu->nr - 1;
+
+ worker = calloc(nthreads, sizeof(*worker));
+ if (!worker) {
+ goto errmem;
+ }
+
+ if (getrlimit(RLIMIT_NOFILE, &prevrl))
+ err(EXIT_FAILURE, "getrlimit");
+ rl.rlim_cur = rl.rlim_max = nfds * nthreads * 2 + 50;
+ printinfo("Setting RLIMIT_NOFILE rlimit from %" PRIu64 " to: %" PRIu64 "\n",
+ (uint64_t)prevrl.rlim_max, (uint64_t)rl.rlim_max);
+ if (setrlimit(RLIMIT_NOFILE, &rl) < 0)
+ err(EXIT_FAILURE, "setrlimit");
+
+ printf("Run summary [PID %d]: %d threads monitoring%s on "
+ "%d file-descriptors for %d secs.\n\n",
+ getpid(), nthreads, oneshot ? " (EPOLLONESHOT semantics)": "", nfds, nsecs);
+
+ init_stats(&throughput_stats);
+ pthread_mutex_init(&thread_lock, NULL);
+ pthread_cond_init(&thread_parent, NULL);
+ pthread_cond_init(&thread_worker, NULL);
+
+ threads_starting = nthreads;
+
+ gettimeofday(&start, NULL);
+
+ do_threads(worker, cpu);
+
+ pthread_mutex_lock(&thread_lock);
+ while (threads_starting)
+ pthread_cond_wait(&thread_parent, &thread_lock);
+ pthread_cond_broadcast(&thread_worker);
+ pthread_mutex_unlock(&thread_lock);
+
+ /*
+ * At this point the workers should be blocked waiting for read events
+ * to become ready. Launch the writer which will constantly be writing
+ * to each thread's fdmap.
+ */
+ ret = pthread_create(&wthread, NULL, writerfn,
+ (void *)(struct worker *) worker);
+ if (ret)
+ err(EXIT_FAILURE, "pthread_create");
+
+ sleep(nsecs);
+ toggle_done(0, NULL, NULL);
+ printinfo("main thread: toggling done\n");
+
+ sleep(1); /* meh */
+ wdone = true;
+ ret = pthread_join(wthread, NULL);
+ if (ret)
+ err(EXIT_FAILURE, "pthread_join");
+
+ /* cleanup & report results */
+ pthread_cond_destroy(&thread_parent);
+ pthread_cond_destroy(&thread_worker);
+ pthread_mutex_destroy(&thread_lock);
+
+ /* sort the array back before reporting */
+ if (randomize)
+ qsort(worker, nthreads, sizeof(struct worker), cmpworker);
+
+ for (i = 0; i < nthreads; i++) {
+ unsigned long t = worker[i].ops/runtime.tv_sec;
+
+ update_stats(&throughput_stats, t);
+
+ if (nfds == 1)
+ printf("[thread %2d] fdmap: %p [ %04ld ops/sec ]\n",
+ worker[i].tid, &worker[i].fdmap[0], t);
+ else
+ printf("[thread %2d] fdmap: %p ... %p [ %04ld ops/sec ]\n",
+ worker[i].tid, &worker[i].fdmap[0],
+ &worker[i].fdmap[nfds-1], t);
+ }
+
+ print_summary();
+
+ close(epollfd);
+ return ret;
+errmem:
+ err(EXIT_FAILURE, "calloc");
+}
+#endif // HAVE_EVENTFD
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index 17a6bcd01aa6..55efd23c3efb 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c
@@ -14,6 +14,7 @@
* mem ... memory access performance
* numa ... NUMA scheduling and MM performance
* futex ... Futex performance
+ * epoll ... Event poll performance
*/
#include "perf.h"
#include "util/util.h"
@@ -67,6 +68,14 @@ static struct bench futex_benchmarks[] = {
{ NULL, NULL, NULL }
};

+#ifdef HAVE_EVENTFD
+static struct bench epoll_benchmarks[] = {
+ { "wait", "Benchmark epoll concurrent epoll_waits", bench_epoll_wait },
+ { "all", "Run all futex benchmarks", NULL },
+ { NULL, NULL, NULL }
+};
+#endif // HAVE_EVENTFD
+
struct collection {
const char *name;
const char *summary;
@@ -80,6 +89,9 @@ static struct collection collections[] = {
{ "numa", "NUMA scheduling and MM benchmarks", numa_benchmarks },
#endif
{"futex", "Futex stressing benchmarks", futex_benchmarks },
+#ifdef HAVE_EVENTFD
+ {"epoll", "Epoll stressing benchmarks", epoll_benchmarks },
+#endif
{ "all", "All benchmarks", NULL },
{ NULL, NULL, NULL }
};

2018-11-22 21:51:13

by tip-bot for Vasyl Gomonovych

[permalink] [raw]

Subject: [tip:perf/core] perf bench: Add epoll_ctl(2) benchmark

Commit-ID: 231457ec707475c71d4e538a3253f1ed9e294cf0
Gitweb: https://git.kernel.org/tip/231457ec707475c71d4e538a3253f1ed9e294cf0
Author: Davidlohr Bueso <[email protected]>
AuthorDate: Tue, 6 Nov 2018 07:22:26 -0800
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Wed, 21 Nov 2018 22:39:55 -0300

perf bench: Add epoll_ctl(2) benchmark

Benchmark the various operations allowed for epoll_ctl(2). The idea is
to concurrently stress a single epoll instance doing add/mod/del
operations.

Committer testing:

# perf bench epoll ctl
# Running 'epoll/ctl' benchmark:
Run summary [PID 20344]: 4 threads doing epoll_ctl ops 64 file-descriptors for 8 secs.

[thread 0] fdmap: 0x21a46b0 ... 0x21a47ac [ add: 1680960 ops; mod: 1680960 ops; del: 1680960 ops ]
[thread 1] fdmap: 0x21a4960 ... 0x21a4a5c [ add: 1685440 ops; mod: 1685440 ops; del: 1685440 ops ]
[thread 2] fdmap: 0x21a4c10 ... 0x21a4d0c [ add: 1674368 ops; mod: 1674368 ops; del: 1674368 ops ]
[thread 3] fdmap: 0x21a4ec0 ... 0x21a4fbc [ add: 1677568 ops; mod: 1677568 ops; del: 1677568 ops ]

Averaged 1679584 ADD operations (+- 0.14%)
Averaged 1679584 MOD operations (+- 0.14%)
Averaged 1679584 DEL operations (+- 0.14%)
#

Lets measure those calls with 'perf trace' to get a glympse at what this
benchmark is doing in terms of syscalls:

# perf trace -m32768 -s perf bench epoll ctl
# Running 'epoll/ctl' benchmark:
Run summary [PID 20405]: 4 threads doing epoll_ctl ops 64 file-descriptors for 8 secs.

[thread 0] fdmap: 0x21764e0 ... 0x21765dc [ add: 1100480 ops; mod: 1100480 ops; del: 1100480 ops ]
[thread 1] fdmap: 0x2176790 ... 0x217688c [ add: 1250176 ops; mod: 1250176 ops; del: 1250176 ops ]
[thread 2] fdmap: 0x2176a40 ... 0x2176b3c [ add: 1022464 ops; mod: 1022464 ops; del: 1022464 ops ]
[thread 3] fdmap: 0x2176cf0 ... 0x2176dec [ add: 705472 ops; mod: 705472 ops; del: 705472 ops ]

Averaged 1019648 ADD operations (+- 11.27%)
Averaged 1019648 MOD operations (+- 11.27%)
Averaged 1019648 DEL operations (+- 11.27%)

Summary of events:

epoll-ctl (20405), 1264 events, 0.0%

syscall calls total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- --------- --------- --------- --------- ------
eventfd2 256 9.514 0.001 0.037 5.243 68.00%
clone 4 1.245 0.204 0.311 0.531 24.13%
mprotect 66 0.345 0.002 0.005 0.021 7.43%
openat 45 0.313 0.004 0.007 0.073 21.93%
mmap 88 0.302 0.002 0.003 0.013 5.02%
futex 4 0.160 0.002 0.040 0.140 83.43%
sched_setaffinity 4 0.124 0.005 0.031 0.070 49.39%
read 44 0.103 0.001 0.002 0.013 15.54%
fstat 40 0.052 0.001 0.001 0.003 5.43%
close 39 0.039 0.001 0.001 0.001 1.48%
stat 9 0.034 0.003 0.004 0.006 7.30%
access 3 0.023 0.007 0.008 0.008 4.25%
open 2 0.021 0.008 0.011 0.013 22.60%
getdents 4 0.019 0.001 0.005 0.009 37.15%
write 2 0.013 0.004 0.007 0.009 38.48%
munmap 1 0.010 0.010 0.010 0.010 0.00%
brk 3 0.006 0.001 0.002 0.003 26.34%
rt_sigprocmask 2 0.004 0.001 0.002 0.003 43.95%
rt_sigaction 3 0.004 0.001 0.001 0.002 16.07%
prlimit64 3 0.004 0.001 0.001 0.001 5.39%
prctl 1 0.003 0.003 0.003 0.003 0.00%
epoll_create 1 0.003 0.003 0.003 0.003 0.00%
lseek 2 0.002 0.001 0.001 0.001 11.42%
sched_getaffinity 1 0.002 0.002 0.002 0.002 0.00%
arch_prctl 1 0.002 0.002 0.002 0.002 0.00%
set_tid_address 1 0.001 0.001 0.001 0.001 0.00%
getpid 1 0.001 0.001 0.001 0.001 0.00%
set_robust_list 1 0.001 0.001 0.001 0.001 0.00%
execve 1 0.000 0.000 0.000 0.000 0.00%

epoll-ctl (20406), 1245480 events, 14.6%

syscall calls total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- --------- --------- --------- --------- ------
epoll_ctl 619511 1034.927 0.001 0.002 6.691 0.67%
nanosleep 3226 616.114 0.006 0.191 10.376 7.57%
futex 2 11.336 0.002 5.668 11.334 99.97%
set_robust_list 1 0.001 0.001 0.001 0.001 0.00%
clone 1 0.000 0.000 0.000 0.000 0.00%

epoll-ctl (20407), 1243151 events, 14.5%

syscall calls total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- --------- --------- --------- --------- ------
epoll_ctl 618350 1042.181 0.001 0.002 2.512 0.40%
nanosleep 3220 366.261 0.012 0.114 18.162 9.59%
futex 4 5.463 0.001 1.366 5.427 99.12%
set_robust_list 1 0.002 0.002 0.002 0.002 0.00%

epoll-ctl (20408), 1801690 events, 21.1%

syscall calls total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- --------- --------- --------- --------- ------
epoll_ctl 896174 1540.581 0.001 0.002 6.987 0.74%
nanosleep 4667 783.393 0.006 0.168 10.419 7.10%
futex 2 4.682 0.002 2.341 4.681 99.93%
set_robust_list 1 0.002 0.002 0.002 0.002 0.00%
clone 1 0.000 0.000 0.000 0.000 0.00%

epoll-ctl (20409), 4254890 events, 49.8%

syscall calls total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- --------- --------- --------- --------- ------
epoll_ctl 2116416 3768.097 0.001 0.002 9.956 0.41%
nanosleep 11023 1141.778 0.006 0.104 9.447 4.95%
futex 3 0.037 0.002 0.012 0.029 70.50%
set_robust_list 1 0.008 0.008 0.008 0.008 0.00%
madvise 1 0.005 0.005 0.005 0.005 0.00%
clone 1 0.000 0.000 0.000 0.000 0.00%
#

Committer notes:

Fix build on fedora:24-x-ARC-uClibc, debian:experimental-x-mips,
debian:experimental-x-mipsel, ubuntu:16.04-x-arm and ubuntu:16.04-x-powerpc

CC /tmp/build/perf/bench/epoll-ctl.o
bench/epoll-ctl.c: In function 'init_fdmaps':
bench/epoll-ctl.c:214:16: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
for (i = 0; i < nfds; i+=inc) {
^
bench/epoll-ctl.c: In function 'bench_epoll_ctl':
bench/epoll-ctl.c:377:16: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
for (i = 0; i < nthreads; i++) {
^
bench/epoll-ctl.c:388:16: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
for (i = 0; i < nthreads; i++) {
^
cc1: all warnings being treated as errors

Signed-off-by: Davidlohr Bueso <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Jason Baron <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Use inttypes.h to print rlim_t fields, fixing the build on Alpine Linux / musl libc ]
[ Check if eventfd() is available, i.e. if HAVE_EVENTFD is defined ]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/Documentation/perf-bench.txt | 3 +
tools/perf/bench/Build | 1 +
tools/perf/bench/bench.h | 1 +
tools/perf/bench/epoll-ctl.c | 413 ++++++++++++++++++++++++++++++++
tools/perf/builtin-bench.c | 1 +
5 files changed, 419 insertions(+)

diff --git a/tools/perf/Documentation/perf-bench.txt b/tools/perf/Documentation/perf-bench.txt
index 3a6b2e73b2e8..0921a3c67381 100644
--- a/tools/perf/Documentation/perf-bench.txt
+++ b/tools/perf/Documentation/perf-bench.txt
@@ -211,6 +211,9 @@ SUITES FOR 'epoll'
*wait*::
Suite for evaluating concurrent epoll_wait calls.

+*ctl*::
+Suite for evaluating multiple epoll_ctl calls.
+
SEE ALSO
--------
linkperf:perf[1]
diff --git a/tools/perf/bench/Build b/tools/perf/bench/Build
index 2bb79b542d53..e4e321b6f883 100644
--- a/tools/perf/bench/Build
+++ b/tools/perf/bench/Build
@@ -8,6 +8,7 @@ perf-y += futex-requeue.o
perf-y += futex-lock-pi.o

perf-y += epoll-wait.o
+perf-y += epoll-ctl.o

perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-lib.o
perf-$(CONFIG_X86_64) += mem-memcpy-x86-64-asm.o
diff --git a/tools/perf/bench/bench.h b/tools/perf/bench/bench.h
index 6e1f091ced96..fddb3ced9db6 100644
--- a/tools/perf/bench/bench.h
+++ b/tools/perf/bench/bench.h
@@ -39,6 +39,7 @@ int bench_futex_requeue(int argc, const char **argv);
int bench_futex_lock_pi(int argc, const char **argv);

int bench_epoll_wait(int argc, const char **argv);
+int bench_epoll_ctl(int argc, const char **argv);

#define BENCH_FORMAT_DEFAULT_STR "default"
#define BENCH_FORMAT_DEFAULT 0
diff --git a/tools/perf/bench/epoll-ctl.c b/tools/perf/bench/epoll-ctl.c
new file mode 100644
index 000000000000..0c0a6e824934
--- /dev/null
+++ b/tools/perf/bench/epoll-ctl.c
@@ -0,0 +1,413 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Davidlohr Bueso.
+ *
+ * Benchmark the various operations allowed for epoll_ctl(2).
+ * The idea is to concurrently stress a single epoll instance
+ */
+#ifdef HAVE_EVENTFD
+/* For the CLR_() macros */
+#include <string.h>
+#include <pthread.h>
+
+#include <errno.h>
+#include <inttypes.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/epoll.h>
+#include <sys/eventfd.h>
+
+#include "../util/stat.h"
+#include <subcmd/parse-options.h>
+#include "bench.h"
+#include "cpumap.h"
+
+#include <err.h>
+
+#define printinfo(fmt, arg...) \
+ do { if (__verbose) printf(fmt, ## arg); } while (0)
+
+static unsigned int nthreads = 0;
+static unsigned int nsecs = 8;
+struct timeval start, end, runtime;
+static bool done, __verbose, randomize;
+
+/*
+ * epoll related shared variables.
+ */
+
+/* Maximum number of nesting allowed inside epoll sets */
+#define EPOLL_MAXNESTS 4
+
+enum {
+ OP_EPOLL_ADD,
+ OP_EPOLL_MOD,
+ OP_EPOLL_DEL,
+ EPOLL_NR_OPS,
+};
+
+static int epollfd;
+static int *epollfdp;
+static bool noaffinity;
+static unsigned int nested = 0;
+
+/* amount of fds to monitor, per thread */
+static unsigned int nfds = 64;
+
+static pthread_mutex_t thread_lock;
+static unsigned int threads_starting;
+static struct stats all_stats[EPOLL_NR_OPS];
+static pthread_cond_t thread_parent, thread_worker;
+
+struct worker {
+ int tid;
+ pthread_t thread;
+ unsigned long ops[EPOLL_NR_OPS];
+ int *fdmap;
+};
+
+static const struct option options[] = {
+ OPT_UINTEGER('t', "threads", &nthreads, "Specify amount of threads"),
+ OPT_UINTEGER('r', "runtime", &nsecs, "Specify runtime (in seconds)"),
+ OPT_UINTEGER('f', "nfds", &nfds, "Specify amount of file descriptors to monitor for each thread"),
+ OPT_BOOLEAN( 'n', "noaffinity", &noaffinity, "Disables CPU affinity"),
+ OPT_UINTEGER( 'N', "nested", &nested, "Nesting level epoll hierarchy (default is 0, no nesting)"),
+ OPT_BOOLEAN( 'R', "randomize", &randomize, "Perform random operations on random fds"),
+ OPT_BOOLEAN( 'v', "verbose", &__verbose, "Verbose mode"),
+ OPT_END()
+};
+
+static const char * const bench_epoll_ctl_usage[] = {
+ "perf bench epoll ctl <options>",
+ NULL
+};
+
+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);
+}
+
+static void nest_epollfd(void)
+{
+ unsigned int i;
+ struct epoll_event ev;
+
+ if (nested > EPOLL_MAXNESTS)
+ nested = EPOLL_MAXNESTS;
+ printinfo("Nesting level(s): %d\n", nested);
+
+ epollfdp = calloc(nested, sizeof(int));
+ if (!epollfd)
+ err(EXIT_FAILURE, "calloc");
+
+ for (i = 0; i < nested; i++) {
+ epollfdp[i] = epoll_create(1);
+ if (epollfd < 0)
+ err(EXIT_FAILURE, "epoll_create");
+ }
+
+ ev.events = EPOLLHUP; /* anything */
+ ev.data.u64 = i; /* any number */
+
+ for (i = nested - 1; i; i--) {
+ if (epoll_ctl(epollfdp[i - 1], EPOLL_CTL_ADD,
+ epollfdp[i], &ev) < 0)
+ err(EXIT_FAILURE, "epoll_ctl");
+ }
+
+ if (epoll_ctl(epollfd, EPOLL_CTL_ADD, *epollfdp, &ev) < 0)
+ err(EXIT_FAILURE, "epoll_ctl");
+}
+
+static inline void do_epoll_op(struct worker *w, int op, int fd)
+{
+ int error;
+ struct epoll_event ev;
+
+ ev.events = EPOLLIN;
+ ev.data.u64 = fd;
+
+ switch (op) {
+ case OP_EPOLL_ADD:
+ error = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev);
+ break;
+ case OP_EPOLL_MOD:
+ ev.events = EPOLLOUT;
+ error = epoll_ctl(epollfd, EPOLL_CTL_MOD, fd, &ev);
+ break;
+ case OP_EPOLL_DEL:
+ error = epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, NULL);
+ break;
+ default:
+ error = 1;
+ break;
+ }
+
+ if (!error)
+ w->ops[op]++;
+}
+
+static inline void do_random_epoll_op(struct worker *w)
+{
+ unsigned long rnd1 = random(), rnd2 = random();
+ int op, fd;
+
+ fd = w->fdmap[rnd1 % nfds];
+ op = rnd2 % EPOLL_NR_OPS;
+
+ do_epoll_op(w, op, fd);
+}
+
+static void *workerfn(void *arg)
+{
+ unsigned int i;
+ struct worker *w = (struct worker *) arg;
+ struct timespec ts = { .tv_sec = 0,
+ .tv_nsec = 250 };
+
+ pthread_mutex_lock(&thread_lock);
+ threads_starting--;
+ if (!threads_starting)
+ pthread_cond_signal(&thread_parent);
+ pthread_cond_wait(&thread_worker, &thread_lock);
+ pthread_mutex_unlock(&thread_lock);
+
+ /* Let 'em loose */
+ do {
+ /* random */
+ if (randomize) {
+ do_random_epoll_op(w);
+ } else {
+ for (i = 0; i < nfds; i++) {
+ do_epoll_op(w, OP_EPOLL_ADD, w->fdmap[i]);
+ do_epoll_op(w, OP_EPOLL_MOD, w->fdmap[i]);
+ do_epoll_op(w, OP_EPOLL_DEL, w->fdmap[i]);
+ }
+ }
+
+ nanosleep(&ts, NULL);
+ } while (!done);
+
+ return NULL;
+}
+
+static void init_fdmaps(struct worker *w, int pct)
+{
+ unsigned int i;
+ int inc;
+ struct epoll_event ev;
+
+ if (!pct)
+ return;
+
+ inc = 100/pct;
+ for (i = 0; i < nfds; i+=inc) {
+ ev.data.fd = w->fdmap[i];
+ ev.events = EPOLLIN;
+
+ if (epoll_ctl(epollfd, EPOLL_CTL_ADD, w->fdmap[i], &ev) < 0)
+ err(EXIT_FAILURE, "epoll_ct");
+ }
+}
+
+static int do_threads(struct worker *worker, struct cpu_map *cpu)
+{
+ pthread_attr_t thread_attr, *attrp = NULL;
+ cpu_set_t cpuset;
+ unsigned int i, j;
+ int ret;
+
+ if (!noaffinity)
+ pthread_attr_init(&thread_attr);
+
+ for (i = 0; i < nthreads; i++) {
+ struct worker *w = &worker[i];
+
+ w->tid = i;
+ w->fdmap = calloc(nfds, sizeof(int));
+ if (!w->fdmap)
+ return 1;
+
+ for (j = 0; j < nfds; j++) {
+ w->fdmap[j] = eventfd(0, EFD_NONBLOCK);
+ if (w->fdmap[j] < 0)
+ err(EXIT_FAILURE, "eventfd");
+ }
+
+ /*
+ * Lets add 50% of the fdmap to the epoll instance, and
+ * do it before any threads are started; otherwise there is
+ * an initial bias of the call failing (mod and del ops).
+ */
+ if (randomize)
+ init_fdmaps(w, 50);
+
+ if (!noaffinity) {
+ CPU_ZERO(&cpuset);
+ CPU_SET(cpu->map[i % cpu->nr], &cpuset);
+
+ ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t), &cpuset);
+ if (ret)
+ err(EXIT_FAILURE, "pthread_attr_setaffinity_np");
+
+ attrp = &thread_attr;
+ }
+
+ ret = pthread_create(&w->thread, attrp, workerfn,
+ (void *)(struct worker *) w);
+ if (ret)
+ err(EXIT_FAILURE, "pthread_create");
+ }
+
+ if (!noaffinity)
+ pthread_attr_destroy(&thread_attr);
+
+ return ret;
+}
+
+static void print_summary(void)
+{
+ int i;
+ unsigned long avg[EPOLL_NR_OPS];
+ double stddev[EPOLL_NR_OPS];
+
+ for (i = 0; i < EPOLL_NR_OPS; i++) {
+ avg[i] = avg_stats(&all_stats[i]);
+ stddev[i] = stddev_stats(&all_stats[i]);
+ }
+
+ printf("\nAveraged %ld ADD operations (+- %.2f%%)\n",
+ avg[OP_EPOLL_ADD], rel_stddev_stats(stddev[OP_EPOLL_ADD],
+ avg[OP_EPOLL_ADD]));
+ printf("Averaged %ld MOD operations (+- %.2f%%)\n",
+ avg[OP_EPOLL_MOD], rel_stddev_stats(stddev[OP_EPOLL_MOD],
+ avg[OP_EPOLL_MOD]));
+ printf("Averaged %ld DEL operations (+- %.2f%%)\n",
+ avg[OP_EPOLL_DEL], rel_stddev_stats(stddev[OP_EPOLL_DEL],
+ avg[OP_EPOLL_DEL]));
+}
+
+int bench_epoll_ctl(int argc, const char **argv)
+{
+ int j, ret = 0;
+ struct sigaction act;
+ struct worker *worker = NULL;
+ struct cpu_map *cpu;
+ struct rlimit rl, prevrl;
+ unsigned int i;
+
+ argc = parse_options(argc, argv, options, bench_epoll_ctl_usage, 0);
+ if (argc) {
+ usage_with_options(bench_epoll_ctl_usage, options);
+ exit(EXIT_FAILURE);
+ }
+
+ sigfillset(&act.sa_mask);
+ act.sa_sigaction = toggle_done;
+ sigaction(SIGINT, &act, NULL);
+
+ cpu = cpu_map__new(NULL);
+ if (!cpu)
+ goto errmem;
+
+ /* a single, main epoll instance */
+ epollfd = epoll_create(1);
+ if (epollfd < 0)
+ err(EXIT_FAILURE, "epoll_create");
+
+ /*
+ * Deal with nested epolls, if any.
+ */
+ if (nested)
+ nest_epollfd();
+
+ /* default to the number of CPUs */
+ if (!nthreads)
+ nthreads = cpu->nr;
+
+ worker = calloc(nthreads, sizeof(*worker));
+ if (!worker)
+ goto errmem;
+
+ if (getrlimit(RLIMIT_NOFILE, &prevrl))
+ err(EXIT_FAILURE, "getrlimit");
+ rl.rlim_cur = rl.rlim_max = nfds * nthreads * 2 + 50;
+ printinfo("Setting RLIMIT_NOFILE rlimit from %" PRIu64 " to: %" PRIu64 "\n",
+ (uint64_t)prevrl.rlim_max, (uint64_t)rl.rlim_max);
+ if (setrlimit(RLIMIT_NOFILE, &rl) < 0)
+ err(EXIT_FAILURE, "setrlimit");
+
+ printf("Run summary [PID %d]: %d threads doing epoll_ctl ops "
+ "%d file-descriptors for %d secs.\n\n",
+ getpid(), nthreads, nfds, nsecs);
+
+ for (i = 0; i < EPOLL_NR_OPS; i++)
+ init_stats(&all_stats[i]);
+
+ pthread_mutex_init(&thread_lock, NULL);
+ pthread_cond_init(&thread_parent, NULL);
+ pthread_cond_init(&thread_worker, NULL);
+
+ threads_starting = nthreads;
+
+ gettimeofday(&start, NULL);
+
+ do_threads(worker, cpu);
+
+ pthread_mutex_lock(&thread_lock);
+ while (threads_starting)
+ pthread_cond_wait(&thread_parent, &thread_lock);
+ pthread_cond_broadcast(&thread_worker);
+ pthread_mutex_unlock(&thread_lock);
+
+ sleep(nsecs);
+ toggle_done(0, NULL, NULL);
+ printinfo("main thread: toggling done\n");
+
+ for (i = 0; i < nthreads; i++) {
+ ret = pthread_join(worker[i].thread, NULL);
+ if (ret)
+ err(EXIT_FAILURE, "pthread_join");
+ }
+
+ /* cleanup & report results */
+ pthread_cond_destroy(&thread_parent);
+ pthread_cond_destroy(&thread_worker);
+ pthread_mutex_destroy(&thread_lock);
+
+ for (i = 0; i < nthreads; i++) {
+ unsigned long t[EPOLL_NR_OPS];
+
+ for (j = 0; j < EPOLL_NR_OPS; j++) {
+ t[j] = worker[i].ops[j];
+ update_stats(&all_stats[j], t[j]);
+ }
+
+ if (nfds == 1)
+ printf("[thread %2d] fdmap: %p [ add: %04ld; mod: %04ld; del: %04lds ops ]\n",
+ worker[i].tid, &worker[i].fdmap[0],
+ t[OP_EPOLL_ADD], t[OP_EPOLL_MOD], t[OP_EPOLL_DEL]);
+ else
+ printf("[thread %2d] fdmap: %p ... %p [ add: %04ld ops; mod: %04ld ops; del: %04ld ops ]\n",
+ worker[i].tid, &worker[i].fdmap[0],
+ &worker[i].fdmap[nfds-1],
+ t[OP_EPOLL_ADD], t[OP_EPOLL_MOD], t[OP_EPOLL_DEL]);
+ }
+
+ print_summary();
+
+ close(epollfd);
+ return ret;
+errmem:
+ err(EXIT_FAILURE, "calloc");
+}
+#endif // HAVE_EVENTFD
diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c
index 55efd23c3efb..334c77ffc1d9 100644
--- a/tools/perf/builtin-bench.c
+++ b/tools/perf/builtin-bench.c
@@ -71,6 +71,7 @@ static struct bench futex_benchmarks[] = {
#ifdef HAVE_EVENTFD
static struct bench epoll_benchmarks[] = {
{ "wait", "Benchmark epoll concurrent epoll_waits", bench_epoll_wait },
+ { "ctl", "Benchmark epoll concurrent epoll_ctls", bench_epoll_ctl },
{ "all", "Run all futex benchmarks", NULL },
{ NULL, NULL, NULL }
};