From 231457ec707475c71d4e538a3253f1ed9e294cf0 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Tue, 6 Nov 2018 07:22:26 -0800 Subject: [PATCH] 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 Tested-by: Arnaldo Carvalho de Melo Cc: Andrew Morton Cc: Davidlohr Bueso Cc: Jason Baron Link: http://lkml.kernel.org/r/20181106152226.20883-3-dave@stgolabs.net [ 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 --- 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(+) create mode 100644 tools/perf/bench/epoll-ctl.c 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 +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../util/stat.h" +#include +#include "bench.h" +#include "cpumap.h" + +#include + +#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 ", + 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 } }; -- 2.30.2