--- /dev/null
+// 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
git.samba.org / sfrench / cifs-2.6.git / commitdiff