From 47e6b251a5e9a47c406f2f2c0b01bb88854c98ec Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 24 May 2012 18:03:13 +0200 Subject: block: switch posix-aio-compat to threadpool This is not meant for portability, but to remove code duplication. Signed-off-by: Paolo Bonzini --- block/raw-posix-aio.h | 1 - block/raw-posix.c | 12 +- posix-aio-compat.c | 427 +++++--------------------------------------------- 3 files changed, 41 insertions(+), 399 deletions(-) diff --git a/block/raw-posix-aio.h b/block/raw-posix-aio.h index ba118f616b..6725135dd4 100644 --- a/block/raw-posix-aio.h +++ b/block/raw-posix-aio.h @@ -28,7 +28,6 @@ /* posix-aio-compat.c - thread pool based implementation */ -int paio_init(void); BlockDriverAIOCB *paio_submit(BlockDriverState *bs, int fd, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockDriverCompletionFunc *cb, void *opaque, int type); diff --git a/block/raw-posix.c b/block/raw-posix.c index 28d439fa81..9ae2c505a8 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -266,14 +266,10 @@ static int raw_open_common(BlockDriverState *bs, const char *filename, } s->fd = fd; - /* We're falling back to POSIX AIO in some cases so init always */ - if (paio_init() < 0) { - goto out_close; - } - #ifdef CONFIG_LINUX_AIO if (raw_set_aio(&s->aio_ctx, &s->use_aio, bdrv_flags)) { - goto out_close; + qemu_close(fd); + return -errno; } #endif @@ -284,10 +280,6 @@ static int raw_open_common(BlockDriverState *bs, const char *filename, #endif return 0; - -out_close: - qemu_close(fd); - return -errno; } static int raw_open(BlockDriverState *bs, const char *filename, int flags) diff --git a/posix-aio-compat.c b/posix-aio-compat.c index 96e4daf505..4a1e3d3662 100644 --- a/posix-aio-compat.c +++ b/posix-aio-compat.c @@ -28,13 +28,12 @@ #include "sysemu.h" #include "qemu-common.h" #include "trace.h" +#include "thread-pool.h" #include "block_int.h" #include "iov.h" #include "block/raw-posix-aio.h" -static void do_spawn_thread(void); - struct qemu_paiocb { BlockDriverAIOCB common; int aio_fildes; @@ -46,82 +45,15 @@ struct qemu_paiocb { size_t aio_nbytes; #define aio_ioctl_cmd aio_nbytes /* for QEMU_AIO_IOCTL */ off_t aio_offset; - - QTAILQ_ENTRY(qemu_paiocb) node; int aio_type; - ssize_t ret; - int active; - struct qemu_paiocb *next; }; -typedef struct PosixAioState { - int rfd, wfd; - struct qemu_paiocb *first_aio; -} PosixAioState; - - -static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER; -static pthread_cond_t cond = PTHREAD_COND_INITIALIZER; -static pthread_t thread_id; -static pthread_attr_t attr; -static int max_threads = 64; -static int cur_threads = 0; -static int idle_threads = 0; -static int new_threads = 0; /* backlog of threads we need to create */ -static int pending_threads = 0; /* threads created but not running yet */ -static QEMUBH *new_thread_bh; -static QTAILQ_HEAD(, qemu_paiocb) request_list; - #ifdef CONFIG_PREADV static int preadv_present = 1; #else static int preadv_present = 0; #endif -static void die2(int err, const char *what) -{ - fprintf(stderr, "%s failed: %s\n", what, strerror(err)); - abort(); -} - -static void die(const char *what) -{ - die2(errno, what); -} - -static void mutex_lock(pthread_mutex_t *mutex) -{ - int ret = pthread_mutex_lock(mutex); - if (ret) die2(ret, "pthread_mutex_lock"); -} - -static void mutex_unlock(pthread_mutex_t *mutex) -{ - int ret = pthread_mutex_unlock(mutex); - if (ret) die2(ret, "pthread_mutex_unlock"); -} - -static int cond_timedwait(pthread_cond_t *cond, pthread_mutex_t *mutex, - struct timespec *ts) -{ - int ret = pthread_cond_timedwait(cond, mutex, ts); - if (ret && ret != ETIMEDOUT) die2(ret, "pthread_cond_timedwait"); - return ret; -} - -static void cond_signal(pthread_cond_t *cond) -{ - int ret = pthread_cond_signal(cond); - if (ret) die2(ret, "pthread_cond_signal"); -} - -static void thread_create(pthread_t *thread, pthread_attr_t *attr, - void *(*start_routine)(void*), void *arg) -{ - int ret = pthread_create(thread, attr, start_routine, arg); - if (ret) die2(ret, "pthread_create"); -} - static ssize_t handle_aiocb_ioctl(struct qemu_paiocb *aiocb) { int ret; @@ -310,286 +242,54 @@ static ssize_t handle_aiocb_rw(struct qemu_paiocb *aiocb) return nbytes; } -static void posix_aio_notify_event(void); - -static void *aio_thread(void *unused) +static int aio_worker(void *arg) { - mutex_lock(&lock); - pending_threads--; - mutex_unlock(&lock); - do_spawn_thread(); - - while (1) { - struct qemu_paiocb *aiocb; - ssize_t ret = 0; - qemu_timeval tv; - struct timespec ts; - - qemu_gettimeofday(&tv); - ts.tv_sec = tv.tv_sec + 10; - ts.tv_nsec = 0; - - mutex_lock(&lock); - - while (QTAILQ_EMPTY(&request_list) && - !(ret == ETIMEDOUT)) { - idle_threads++; - ret = cond_timedwait(&cond, &lock, &ts); - idle_threads--; + struct qemu_paiocb *aiocb = arg; + ssize_t ret = 0; + + switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) { + case QEMU_AIO_READ: + ret = handle_aiocb_rw(aiocb); + if (ret >= 0 && ret < aiocb->aio_nbytes && aiocb->common.bs->growable) { + /* A short read means that we have reached EOF. Pad the buffer + * with zeros for bytes after EOF. */ + iov_memset(aiocb->aio_iov, aiocb->aio_niov, ret, + 0, aiocb->aio_nbytes - ret); + + ret = aiocb->aio_nbytes; } - - if (QTAILQ_EMPTY(&request_list)) - break; - - aiocb = QTAILQ_FIRST(&request_list); - QTAILQ_REMOVE(&request_list, aiocb, node); - aiocb->active = 1; - mutex_unlock(&lock); - - switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) { - case QEMU_AIO_READ: - ret = handle_aiocb_rw(aiocb); - if (ret >= 0 && ret < aiocb->aio_nbytes && aiocb->common.bs->growable) { - /* A short read means that we have reached EOF. Pad the buffer - * with zeros for bytes after EOF. */ - iov_memset(aiocb->aio_iov, aiocb->aio_niov, ret, - 0, aiocb->aio_nbytes - ret); - - ret = aiocb->aio_nbytes; - } - break; - case QEMU_AIO_WRITE: - ret = handle_aiocb_rw(aiocb); - break; - case QEMU_AIO_FLUSH: - ret = handle_aiocb_flush(aiocb); - break; - case QEMU_AIO_IOCTL: - ret = handle_aiocb_ioctl(aiocb); - break; - default: - fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type); + if (ret == aiocb->aio_nbytes) { + ret = 0; + } else if (ret >= 0 && ret < aiocb->aio_nbytes) { ret = -EINVAL; - break; } - - mutex_lock(&lock); - aiocb->ret = ret; - mutex_unlock(&lock); - - posix_aio_notify_event(); - } - - cur_threads--; - mutex_unlock(&lock); - - return NULL; -} - -static void do_spawn_thread(void) -{ - sigset_t set, oldset; - - mutex_lock(&lock); - if (!new_threads) { - mutex_unlock(&lock); - return; - } - - new_threads--; - pending_threads++; - - mutex_unlock(&lock); - - /* block all signals */ - if (sigfillset(&set)) die("sigfillset"); - if (sigprocmask(SIG_SETMASK, &set, &oldset)) die("sigprocmask"); - - thread_create(&thread_id, &attr, aio_thread, NULL); - - if (sigprocmask(SIG_SETMASK, &oldset, NULL)) die("sigprocmask restore"); -} - -static void spawn_thread_bh_fn(void *opaque) -{ - do_spawn_thread(); -} - -static void spawn_thread(void) -{ - cur_threads++; - new_threads++; - /* If there are threads being created, they will spawn new workers, so - * we don't spend time creating many threads in a loop holding a mutex or - * starving the current vcpu. - * - * If there are no idle threads, ask the main thread to create one, so we - * inherit the correct affinity instead of the vcpu affinity. - */ - if (!pending_threads) { - qemu_bh_schedule(new_thread_bh); - } -} - -static void qemu_paio_submit(struct qemu_paiocb *aiocb) -{ - aiocb->ret = -EINPROGRESS; - aiocb->active = 0; - mutex_lock(&lock); - if (idle_threads == 0 && cur_threads < max_threads) - spawn_thread(); - QTAILQ_INSERT_TAIL(&request_list, aiocb, node); - mutex_unlock(&lock); - cond_signal(&cond); -} - -static ssize_t qemu_paio_return(struct qemu_paiocb *aiocb) -{ - ssize_t ret; - - mutex_lock(&lock); - ret = aiocb->ret; - mutex_unlock(&lock); - - return ret; -} - -static int qemu_paio_error(struct qemu_paiocb *aiocb) -{ - ssize_t ret = qemu_paio_return(aiocb); - - if (ret < 0) - ret = -ret; - else - ret = 0; - - return ret; -} - -static void posix_aio_read(void *opaque) -{ - PosixAioState *s = opaque; - struct qemu_paiocb *acb, **pacb; - int ret; - ssize_t len; - - /* read all bytes from signal pipe */ - for (;;) { - char bytes[16]; - - len = read(s->rfd, bytes, sizeof(bytes)); - if (len == -1 && errno == EINTR) - continue; /* try again */ - if (len == sizeof(bytes)) - continue; /* more to read */ break; - } - - for(;;) { - pacb = &s->first_aio; - for(;;) { - acb = *pacb; - if (!acb) - return; - - ret = qemu_paio_error(acb); - if (ret == ECANCELED) { - /* remove the request */ - *pacb = acb->next; - qemu_aio_release(acb); - } else if (ret != EINPROGRESS) { - /* end of aio */ - if (ret == 0) { - ret = qemu_paio_return(acb); - if (ret == acb->aio_nbytes) - ret = 0; - else - ret = -EINVAL; - } else { - ret = -ret; - } - - trace_paio_complete(acb, acb->common.opaque, ret); - - /* remove the request */ - *pacb = acb->next; - /* call the callback */ - acb->common.cb(acb->common.opaque, ret); - qemu_aio_release(acb); - break; - } else { - pacb = &acb->next; - } - } - } -} - -static int posix_aio_flush(void *opaque) -{ - PosixAioState *s = opaque; - return !!s->first_aio; -} - -static PosixAioState *posix_aio_state; - -static void posix_aio_notify_event(void) -{ - char byte = 0; - ssize_t ret; - - ret = write(posix_aio_state->wfd, &byte, sizeof(byte)); - if (ret < 0 && errno != EAGAIN) - die("write()"); -} - -static void paio_remove(struct qemu_paiocb *acb) -{ - struct qemu_paiocb **pacb; - - /* remove the callback from the queue */ - pacb = &posix_aio_state->first_aio; - for(;;) { - if (*pacb == NULL) { - fprintf(stderr, "paio_remove: aio request not found!\n"); - break; - } else if (*pacb == acb) { - *pacb = acb->next; - qemu_aio_release(acb); - break; + case QEMU_AIO_WRITE: + ret = handle_aiocb_rw(aiocb); + if (ret == aiocb->aio_nbytes) { + ret = 0; + } else if (ret >= 0 && ret < aiocb->aio_nbytes) { + ret = -EINVAL; } - pacb = &(*pacb)->next; - } -} - -static void paio_cancel(BlockDriverAIOCB *blockacb) -{ - struct qemu_paiocb *acb = (struct qemu_paiocb *)blockacb; - int active = 0; - - trace_paio_cancel(acb, acb->common.opaque); - - mutex_lock(&lock); - if (!acb->active) { - QTAILQ_REMOVE(&request_list, acb, node); - acb->ret = -ECANCELED; - } else if (acb->ret == -EINPROGRESS) { - active = 1; - } - mutex_unlock(&lock); - - if (active) { - /* fail safe: if the aio could not be canceled, we wait for - it */ - while (qemu_paio_error(acb) == EINPROGRESS) - ; + break; + case QEMU_AIO_FLUSH: + ret = handle_aiocb_flush(aiocb); + break; + case QEMU_AIO_IOCTL: + ret = handle_aiocb_ioctl(aiocb); + break; + default: + fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type); + ret = -EINVAL; + break; } - paio_remove(acb); + qemu_aio_release(aiocb); + return ret; } static AIOPool raw_aio_pool = { .aiocb_size = sizeof(struct qemu_paiocb), - .cancel = paio_cancel, }; BlockDriverAIOCB *paio_submit(BlockDriverState *bs, int fd, @@ -609,12 +309,8 @@ BlockDriverAIOCB *paio_submit(BlockDriverState *bs, int fd, acb->aio_nbytes = nb_sectors * 512; acb->aio_offset = sector_num * 512; - acb->next = posix_aio_state->first_aio; - posix_aio_state->first_aio = acb; - trace_paio_submit(acb, opaque, sector_num, nb_sectors, type); - qemu_paio_submit(acb); - return &acb->common; + return thread_pool_submit_aio(aio_worker, acb, cb, opaque); } BlockDriverAIOCB *paio_ioctl(BlockDriverState *bs, int fd, @@ -630,50 +326,5 @@ BlockDriverAIOCB *paio_ioctl(BlockDriverState *bs, int fd, acb->aio_ioctl_buf = buf; acb->aio_ioctl_cmd = req; - acb->next = posix_aio_state->first_aio; - posix_aio_state->first_aio = acb; - - qemu_paio_submit(acb); - return &acb->common; -} - -int paio_init(void) -{ - PosixAioState *s; - int fds[2]; - int ret; - - if (posix_aio_state) - return 0; - - s = g_malloc(sizeof(PosixAioState)); - - s->first_aio = NULL; - if (qemu_pipe(fds) == -1) { - fprintf(stderr, "failed to create pipe\n"); - g_free(s); - return -1; - } - - s->rfd = fds[0]; - s->wfd = fds[1]; - - fcntl(s->rfd, F_SETFL, O_NONBLOCK); - fcntl(s->wfd, F_SETFL, O_NONBLOCK); - - qemu_aio_set_fd_handler(s->rfd, posix_aio_read, NULL, posix_aio_flush, s); - - ret = pthread_attr_init(&attr); - if (ret) - die2(ret, "pthread_attr_init"); - - ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); - if (ret) - die2(ret, "pthread_attr_setdetachstate"); - - QTAILQ_INIT(&request_list); - new_thread_bh = qemu_bh_new(spawn_thread_bh_fn, NULL); - - posix_aio_state = s; - return 0; + return thread_pool_submit_aio(aio_worker, acb, cb, opaque); } -- cgit v1.2.1