From patchwork Tue Jun 11 14:54:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roman Penyaev X-Patchwork-Id: 10987347 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 892D6924 for ; Tue, 11 Jun 2019 14:55:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7669B284F1 for ; Tue, 11 Jun 2019 14:55:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6A3CF20182; Tue, 11 Jun 2019 14:55:42 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 29F802843C for ; Tue, 11 Jun 2019 14:55:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391707AbfFKOzh (ORCPT ); Tue, 11 Jun 2019 10:55:37 -0400 Received: from mx2.suse.de ([195.135.220.15]:52806 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2391683AbfFKOzh (ORCPT ); Tue, 11 Jun 2019 10:55:37 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 69DFEAD5D; Tue, 11 Jun 2019 14:55:35 +0000 (UTC) From: Roman Penyaev Cc: Roman Penyaev , Andrew Morton , Al Viro , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 14/14] kselftest: add uepoll-test which tests polling from userspace Date: Tue, 11 Jun 2019 16:54:58 +0200 Message-Id: <20190611145458.9540-15-rpenyaev@suse.de> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190611145458.9540-1-rpenyaev@suse.de> References: <20190611145458.9540-1-rpenyaev@suse.de> MIME-Version: 1.0 To: unlisted-recipients:; (no To-header on input) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: Roman Penyaev Cc: Andrew Morton Cc: Al Viro Cc: Linus Torvalds Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/uepoll/.gitignore | 1 + tools/testing/selftests/uepoll/Makefile | 16 + .../uepoll/atomic-builtins-support.c | 13 + tools/testing/selftests/uepoll/uepoll-test.c | 603 ++++++++++++++++++ 5 files changed, 634 insertions(+) create mode 100644 tools/testing/selftests/uepoll/.gitignore create mode 100644 tools/testing/selftests/uepoll/Makefile create mode 100644 tools/testing/selftests/uepoll/atomic-builtins-support.c create mode 100644 tools/testing/selftests/uepoll/uepoll-test.c diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 9781ca79794a..ff87ac3400fe 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -52,6 +52,7 @@ TARGETS += timers endif TARGETS += tmpfs TARGETS += tpm2 +TARGETS += uepoll TARGETS += user TARGETS += vm TARGETS += x86 diff --git a/tools/testing/selftests/uepoll/.gitignore b/tools/testing/selftests/uepoll/.gitignore new file mode 100644 index 000000000000..8eedec333023 --- /dev/null +++ b/tools/testing/selftests/uepoll/.gitignore @@ -0,0 +1 @@ +uepoll-test diff --git a/tools/testing/selftests/uepoll/Makefile b/tools/testing/selftests/uepoll/Makefile new file mode 100644 index 000000000000..cc1b2009197d --- /dev/null +++ b/tools/testing/selftests/uepoll/Makefile @@ -0,0 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0 + +CC := $(CROSS_COMPILE)gcc +CFLAGS += -O2 -g -I../../../../usr/include/ -lnuma -lpthread + +BUILTIN_SUPPORT := $(shell $(CC) -o /dev/null ./atomic-builtins-support.c >/dev/null 2>&1; echo $$?) + +ifeq "$(BUILTIN_SUPPORT)" "0" + TEST_GEN_PROGS := uepoll-test +else + $(warning WARNING:) + $(warning WARNING: uepoll compilation is skipped, gcc atomic builtins are not supported!) + $(warning WARNING:) +endif + +include ../lib.mk diff --git a/tools/testing/selftests/uepoll/atomic-builtins-support.c b/tools/testing/selftests/uepoll/atomic-builtins-support.c new file mode 100644 index 000000000000..d9ded39ec497 --- /dev/null +++ b/tools/testing/selftests/uepoll/atomic-builtins-support.c @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Just a test to check if gcc supports atomic builtins + */ +unsigned long long v, vv, vvv; + +int main(void) +{ + vv = __atomic_load_n(&v, __ATOMIC_ACQUIRE); + vvv = __atomic_exchange_n(&vv, 0, __ATOMIC_ACQUIRE); + + return __atomic_add_fetch(&vvv, 1, __ATOMIC_RELAXED); +} diff --git a/tools/testing/selftests/uepoll/uepoll-test.c b/tools/testing/selftests/uepoll/uepoll-test.c new file mode 100644 index 000000000000..1cefdcc1e25b --- /dev/null +++ b/tools/testing/selftests/uepoll/uepoll-test.c @@ -0,0 +1,603 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * uepoll-test.c - Test cases for epoll_create2(), namely pollable + * epoll from userspace. Copyright (c) 2019 Roman Penyaev + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../kselftest.h" +#include "../kselftest_harness.h" + +#include +#include + +#define BUILD_BUG_ON(condition) ((void)sizeof(char [1 - 2*!!(condition)])) +#define READ_ONCE(v) (*(volatile typeof(v)*)&(v)) + +#define ITERS 1000000ull + +/* + * Add main epoll functions manually, because sys/epoll.h conflicts + * with linux/eventpoll.h. + */ +extern int epoll_create1(int __flags); +extern int epoll_ctl(int __epfd, int __op, int __fd, + struct epoll_event *__event); +extern int epoll_wait(int __epfd, struct epoll_event *__events, + int __maxevents, int __timeout); + +static inline long epoll_create2(int flags, size_t size) +{ + return syscall(__NR_epoll_create2, flags, size); +} + +struct thread_ctx { + pthread_t thread; + int efd; +}; + +struct cpu_map { + unsigned int nr; + unsigned int map[]; +}; + +static volatile unsigned int thr_ready; +static volatile unsigned int start; + +static inline unsigned int max_index_nr(struct epoll_uheader *header) +{ + return header->index_length >> 2; +} + +static int is_cpu_online(int cpu) +{ + char buf[64]; + char online; + FILE *f; + int rc; + + snprintf(buf, sizeof(buf), "/sys/devices/system/cpu/cpu%d/online", cpu); + f = fopen(buf, "r"); + if (!f) + return 1; + + rc = fread(&online, 1, 1, f); + assert(rc == 1); + fclose(f); + + return (char)online == '1'; +} + +static struct cpu_map *cpu_map__new(void) +{ + struct cpu_map *cpu; + struct bitmask *bm; + + int i, bit, cpus_nr; + + cpus_nr = numa_num_possible_cpus(); + cpu = calloc(1, sizeof(*cpu) + sizeof(cpu->map[0]) * cpus_nr); + if (!cpu) + return NULL; + + bm = numa_all_cpus_ptr; + assert(bm); + + for (bit = 0, i = 0; bit < bm->size; bit++) { + if (numa_bitmask_isbitset(bm, bit) && is_cpu_online(bit)) { + cpu->map[i++] = bit; + } + } + cpu->nr = i; + + return cpu; +} + +static void cpu_map__put(struct cpu_map *cpu) +{ + free(cpu); +} + +static inline unsigned long long nsecs(void) +{ + struct timespec ts = {0, 0}; + + clock_gettime(CLOCK_MONOTONIC, &ts); + return ((unsigned long long)ts.tv_sec * 1000000000ull) + ts.tv_nsec; +} + +static void *thread_work(void *arg) +{ + struct thread_ctx *ctx = arg; + uint64_t ucnt = 1; + unsigned int i; + int rc; + + __atomic_add_fetch(&thr_ready, 1, __ATOMIC_RELAXED); + + while (!start) + ; + + for (i = 0; i < ITERS; i++) { + rc = write(ctx->efd, &ucnt, sizeof(ucnt)); + assert(rc == sizeof(ucnt)); + } + + return NULL; +} + +static inline _Bool read_event(struct epoll_uheader *header, + unsigned int *index, unsigned int idx, + struct epoll_event *event) +{ + struct epoll_uitem *item; + unsigned int *item_idx_ptr; + unsigned int indeces_mask; + + indeces_mask = max_index_nr(header) - 1; + if (indeces_mask & max_index_nr(header)) { + assert(0); + /* Should be pow2, corrupted header? */ + return 0; + } + + item_idx_ptr = &index[idx & indeces_mask]; + + /* Load index */ + idx = __atomic_load_n(item_idx_ptr, __ATOMIC_ACQUIRE); + if (idx >= header->max_items_nr) { + assert(0); + /* Corrupted index? */ + return 0; + } + + item = &header->items[idx]; + + /* + * Fetch data first, if event is cleared by the kernel we drop the data + * returning false. + */ + event->data = (__u64) item->data; + event->events = __atomic_exchange_n(&item->ready_events, 0, + __ATOMIC_RELEASE); + + return (event->events & ~EPOLLREMOVED); +} + +static int uepoll_wait(struct epoll_uheader *header, unsigned int *index, + int epfd, struct epoll_event *events, int maxevents) + +{ + /* + * Before entering kernel we do busy wait for ~1ms, naively assuming + * each iteration costs 1 cycle, 1 ns. + */ + unsigned int spins = 1000000; + unsigned int tail; + int i; + + assert(maxevents > 0); + +again: + /* + * Cache the tail because we don't want refetch it on each iteration + * and then catch live events updates, i.e. we don't want user @events + * array consist of events from the same fds. + */ + tail = READ_ONCE(header->tail); + + if (header->head == tail) { + if (spins--) + /* Busy loop a bit */ + goto again; + + i = epoll_wait(epfd, NULL, 0, -1); + assert(i < 0); + if (errno != ESTALE) + return i; + + tail = READ_ONCE(header->tail); + assert(header->head != tail); + } + + for (i = 0; header->head != tail && i < maxevents; header->head++) { + if (read_event(header, index, header->head, &events[i])) + i++; + else + /* Event can't be removed under us */ + assert(0); + } + + return i; +} + +static void uepoll_mmap(int epfd, struct epoll_uheader **_header, + unsigned int **_index) +{ + struct epoll_uheader *header; + unsigned int *index, len; + + BUILD_BUG_ON(sizeof(*header) != EPOLL_USERPOLL_HEADER_SIZE); + BUILD_BUG_ON(sizeof(header->items[0]) != 16); + + len = sysconf(_SC_PAGESIZE); +again: + header = mmap(NULL, len, PROT_WRITE|PROT_READ, MAP_SHARED, epfd, 0); + if (header == MAP_FAILED) + ksft_exit_fail_msg("Failed map(header)\n"); + + if (header->header_length != len) { + unsigned int tmp_len = len; + + len = header->header_length; + munmap(header, tmp_len); + goto again; + } + assert(header->magic == EPOLL_USERPOLL_HEADER_MAGIC); + + index = mmap(NULL, header->index_length, PROT_WRITE|PROT_READ, + MAP_SHARED, epfd, header->header_length); + if (index == MAP_FAILED) + ksft_exit_fail_msg("Failed map(index)\n"); + + *_header = header; + *_index = index; +} + +static void uepoll_munmap(struct epoll_uheader *header, + unsigned int *index) +{ + int rc; + + rc = munmap(index, header->index_length); + if (rc) + ksft_exit_fail_msg("Failed munmap(index)\n"); + + rc = munmap(header, header->header_length); + if (rc) + ksft_exit_fail_msg("Failed munmap(header)\n"); +} + +static int do_bench(struct cpu_map *cpu, unsigned int nthreads) +{ + struct epoll_event ev, events[nthreads]; + struct thread_ctx threads[nthreads]; + pthread_attr_t thrattr; + struct thread_ctx *ctx; + int rc, epfd, nfds; + cpu_set_t cpuset; + unsigned int i; + + struct epoll_uheader *header; + unsigned int *index; + + unsigned long long epoll_calls = 0, epoll_nsecs; + unsigned long long ucnt, ucnt_sum = 0, eagains = 0; + + thr_ready = 0; + start = 0; + + epfd = epoll_create2(EPOLL_USERPOLL, nthreads); + if (epfd < 0) + ksft_exit_fail_msg("Failed epoll_create2()\n"); + + for (i = 0; i < nthreads; i++) { + ctx = &threads[i]; + + ctx->efd = eventfd(0, EFD_NONBLOCK); + if (ctx->efd < 0) + ksft_exit_fail_msg("Failed eventfd()\n"); + + ev.events = EPOLLIN | EPOLLET; + ev.data = (uintptr_t) ctx; + rc = epoll_ctl(epfd, EPOLL_CTL_ADD, ctx->efd, &ev); + if (rc) + ksft_exit_fail_msg("Failed epoll_ctl()\n"); + + CPU_ZERO(&cpuset); + CPU_SET(cpu->map[i % cpu->nr], &cpuset); + + pthread_attr_init(&thrattr); + rc = pthread_attr_setaffinity_np(&thrattr, sizeof(cpu_set_t), + &cpuset); + if (rc) { + errno = rc; + ksft_exit_fail_msg("Failed pthread_attr_setaffinity_np()\n"); + } + + rc = pthread_create(&ctx->thread, NULL, thread_work, ctx); + if (rc) { + errno = rc; + ksft_exit_fail_msg("Failed pthread_create()\n"); + } + } + + /* Mmap all pointers */ + uepoll_mmap(epfd, &header, &index); + + while (thr_ready != nthreads) + ; + + /* Signal start for all threads */ + start = 1; + + epoll_nsecs = nsecs(); + while (1) { + nfds = uepoll_wait(header, index, epfd, events, nthreads); + if (nfds < 0) + ksft_exit_fail_msg("Failed uepoll_wait()\n"); + + epoll_calls++; + + for (i = 0; i < (unsigned int)nfds; ++i) { + ctx = (void *)(uintptr_t) events[i].data; + rc = read(ctx->efd, &ucnt, sizeof(ucnt)); + if (rc < 0) { + assert(errno == EAGAIN); + continue; + } + assert(rc == sizeof(ucnt)); + ucnt_sum += ucnt; + if (ucnt_sum == nthreads * ITERS) + goto end; + } + } +end: + epoll_nsecs = nsecs() - epoll_nsecs; + + for (i = 0; i < nthreads; i++) { + ctx = &threads[i]; + pthread_join(ctx->thread, NULL); + } + uepoll_munmap(header, index); + close(epfd); + + ksft_print_msg("%7d %8lld %8lld\n", + nthreads, + ITERS*nthreads/(epoll_nsecs/1000/1000), + epoll_nsecs/1000/1000); + + return 0; +} + +/** + * uepoll loop + */ +TEST(uepoll_basics) +{ + unsigned int i, nthreads_arr[] = {8, 16, 32, 64}; + struct cpu_map *cpu; + + cpu = cpu_map__new(); + if (!cpu) { + errno = ENOMEM; + ksft_exit_fail_msg("Failed cpu_map__new()\n"); + } + + ksft_print_msg("threads events/ms run-time ms\n"); + for (i = 0; i < ARRAY_SIZE(nthreads_arr); i++) + do_bench(cpu, nthreads_arr[i]); + + cpu_map__put(cpu); +} + +/** + * Checks different flags and args + */ +TEST(uepoll_args) +{ + struct epoll_event ev; + int epfd, evfd, rc; + + /* Fail */ + epfd = epoll_create2(EPOLL_USERPOLL, (1<<16)+1); + ASSERT_EQ(errno, EINVAL); + ASSERT_EQ(epfd, -1); + + /* Fail */ + epfd = epoll_create2(EPOLL_USERPOLL, 0); + ASSERT_EQ(errno, EINVAL); + ASSERT_EQ(epfd, -1); + + /* Success */ + epfd = epoll_create2(EPOLL_USERPOLL, (1<<16)); + ASSERT_GE(epfd, 0); + + /* Success */ + evfd = eventfd(0, EFD_NONBLOCK); + ASSERT_GE(evfd, 0); + + /* Fail, expect EPOLLET */ + ev.events = EPOLLIN; + rc = epoll_ctl(epfd, EPOLL_CTL_ADD, evfd, &ev); + ASSERT_EQ(errno, EINVAL); + ASSERT_EQ(rc, -1); + + /* Fail, no support for EPOLLEXCLUSIVE */ + ev.events = EPOLLIN | EPOLLET | EPOLLEXCLUSIVE; + rc = epoll_ctl(epfd, EPOLL_CTL_ADD, evfd, &ev); + ASSERT_EQ(errno, EINVAL); + ASSERT_EQ(rc, -1); + + /* Success */ + ev.events = EPOLLIN | EPOLLET; + rc = epoll_ctl(epfd, EPOLL_CTL_ADD, evfd, &ev); + ASSERT_EQ(rc, 0); + + /* Fail, expect events and maxevents as zeroes */ + rc = epoll_wait(epfd, &ev, 1, -1); + ASSERT_EQ(errno, EINVAL); + ASSERT_EQ(rc, -1); + + /* Fail, expect events as zero */ + rc = epoll_wait(epfd, &ev, 0, -1); + ASSERT_EQ(errno, EINVAL); + ASSERT_EQ(rc, -1); + + /* Fail, expect maxevents as zero */ + rc = epoll_wait(epfd, NULL, 1, -1); + ASSERT_EQ(errno, EINVAL); + ASSERT_EQ(rc, -1); + + /* Success */ + rc = epoll_wait(epfd, NULL, 0, 0); + ASSERT_EQ(rc, 0); + + close(epfd); + close(evfd); +} + +static void *signal_eventfd_work(void *arg) +{ + unsigned long long cnt; + + int rc, evfd = *(int *)arg; + + sleep(1); + cnt = 1; + rc = write(evfd, &cnt, sizeof(cnt)); + assert(rc == 8); + + return NULL; +} + +/** + * Nested poll + */ +TEST(uepoll_poll) +{ + int epfd, uepfd, evfd, rc; + + struct epoll_event ev; + pthread_t thread; + + /* Success */ + uepfd = epoll_create2(EPOLL_USERPOLL, 128); + ASSERT_GE(uepfd, 0); + + /* Success */ + epfd = epoll_create2(0, 0); + ASSERT_GE(epfd, 0); + + /* Success */ + evfd = eventfd(0, EFD_NONBLOCK); + ASSERT_GE(evfd, 0); + + /* Success */ + ev.events = EPOLLIN | EPOLLET; + rc = epoll_ctl(uepfd, EPOLL_CTL_ADD, evfd, &ev); + ASSERT_EQ(rc, 0); + + /* Success */ + ev.events = EPOLLIN | EPOLLET; + rc = epoll_ctl(epfd, EPOLL_CTL_ADD, uepfd, &ev); + ASSERT_EQ(rc, 0); + + /* Success */ + rc = epoll_wait(epfd, &ev, 1, 0); + ASSERT_EQ(rc, 0); + + /* Success */ + rc = pthread_create(&thread, NULL, signal_eventfd_work, &evfd); + ASSERT_EQ(rc, 0); + + /* Success */ + rc = epoll_wait(epfd, &ev, 1, 5000); + ASSERT_EQ(rc, 1); + + close(uepfd); + close(epfd); + close(evfd); +} + +/** + * One shot + */ +TEST(uepoll_epolloneshot) +{ + int epfd, evfd, rc; + unsigned long long cnt; + + struct epoll_uheader *header; + unsigned int *index; + + struct epoll_event ev; + pthread_t thread; + + /* Success */ + epfd = epoll_create2(EPOLL_USERPOLL, 128); + ASSERT_GE(epfd, 0); + + /* Mmap all pointers */ + uepoll_mmap(epfd, &header, &index); + + /* Success */ + evfd = eventfd(0, EFD_NONBLOCK); + ASSERT_GE(evfd, 0); + + /* Success */ + ev.events = EPOLLIN | EPOLLET | EPOLLONESHOT; + rc = epoll_ctl(epfd, EPOLL_CTL_ADD, evfd, &ev); + ASSERT_EQ(rc, 0); + + /* Success */ + rc = pthread_create(&thread, NULL, signal_eventfd_work, &evfd); + ASSERT_EQ(rc, 0); + + /* Fail, expect -ESTALE */ + rc = epoll_wait(epfd, NULL, 0, 3000); + ASSERT_EQ(errno, ESTALE); + ASSERT_EQ(rc, -1); + + /* Success */ + rc = uepoll_wait(header, index, epfd, &ev, 1); + ASSERT_EQ(rc, 1); + + /* Success */ + rc = pthread_create(&thread, NULL, signal_eventfd_work, &evfd); + ASSERT_EQ(rc, 0); + + /* Success */ + rc = epoll_wait(epfd, NULL, 0, 3000); + ASSERT_EQ(rc, 0); + + + /* Success */ + ev.events = EPOLLIN | EPOLLET; + rc = epoll_ctl(epfd, EPOLL_CTL_MOD, evfd, &ev); + ASSERT_EQ(rc, 0); + + /* Success */ + rc = pthread_create(&thread, NULL, signal_eventfd_work, &evfd); + ASSERT_EQ(rc, 0); + + /* Success */ + rc = uepoll_wait(header, index, epfd, &ev, 1); + ASSERT_EQ(rc, 1); + + /* Success */ + rc = pthread_create(&thread, NULL, signal_eventfd_work, &evfd); + ASSERT_EQ(rc, 0); + + /* Success */ + rc = uepoll_wait(header, index, epfd, &ev, 1); + ASSERT_EQ(rc, 1); + + uepoll_munmap(header, index); + close(epfd); + close(evfd); +} + +TEST_HARNESS_MAIN