This patch makes the paio subsystem use the generic work offloading
infrastructure.
The patch has been tested with fstress.
Signed-off-by: Gautham R Shenoy <e...@in.ibm.com>
---
posix-aio-compat.c | 156 ++++++++++------------------------------------------
1 files changed, 30 insertions(+), 126 deletions(-)
diff --git a/posix-aio-compat.c b/posix-aio-compat.c
index b43c531..1b405e4 100644
--- a/posix-aio-compat.c
+++ b/posix-aio-compat.c
@@ -28,6 +28,7 @@
#include "block_int.h"
#include "block/raw-posix-aio.h"
+#include "async-work.h"
struct qemu_paiocb {
@@ -50,6 +51,7 @@ struct qemu_paiocb {
struct qemu_paiocb *next;
int async_context_id;
+ struct work_item *work;
};
typedef struct PosixAioState {
@@ -57,15 +59,8 @@ typedef struct PosixAioState {
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 QTAILQ_HEAD(, qemu_paiocb) request_list;
+static struct async_queue aio_request_list;
#ifdef CONFIG_PREADV
static int preadv_present = 1;
@@ -84,39 +79,6 @@ 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;
@@ -300,47 +262,27 @@ static ssize_t handle_aiocb_rw(struct qemu_paiocb *aiocb)
return nbytes;
}
-static void *aio_thread(void *unused)
+static void aio_thread(struct work_item *work)
{
- pid_t pid;
- pid = getpid();
-
- 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);
+ pid_t pid;
- while (QTAILQ_EMPTY(&request_list) &&
- !(ret == ETIMEDOUT)) {
- ret = cond_timedwait(&cond, &lock, &ts);
- }
+ struct qemu_paiocb *aiocb = (struct qemu_paiocb *) work->private;
+ ssize_t ret = 0;
- if (QTAILQ_EMPTY(&request_list))
- break;
+ pid = getpid();
- aiocb = QTAILQ_FIRST(&request_list);
- QTAILQ_REMOVE(&request_list, aiocb, node);
- aiocb->active = 1;
- idle_threads--;
- mutex_unlock(&lock);
+ aiocb->active = 1;
- switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
- case QEMU_AIO_READ:
- case QEMU_AIO_WRITE:
+ switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
+ case QEMU_AIO_READ:
+ case QEMU_AIO_WRITE:
ret = handle_aiocb_rw(aiocb);
break;
- case QEMU_AIO_FLUSH:
- ret = handle_aiocb_flush(aiocb);
- break;
- case QEMU_AIO_IOCTL:
+ case QEMU_AIO_FLUSH:
+ ret = handle_aiocb_flush(aiocb);
+ break;
+ case QEMU_AIO_IOCTL:
ret = handle_aiocb_ioctl(aiocb);
break;
default:
@@ -349,57 +291,29 @@ static void *aio_thread(void *unused)
break;
}
- mutex_lock(&lock);
- aiocb->ret = ret;
- idle_threads++;
- mutex_unlock(&lock);
-
- if (kill(pid, aiocb->ev_signo)) die("kill failed");
- }
-
- idle_threads--;
- cur_threads--;
- mutex_unlock(&lock);
+ aiocb->ret = ret;
- return NULL;
-}
-
-static void spawn_thread(void)
-{
- sigset_t set, oldset;
-
- cur_threads++;
- idle_threads++;
-
- /* 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");
+ if (kill(pid, aiocb->ev_signo)) die("kill failed");
+ async_work_release(&aio_request_list, work);
}
static void qemu_paio_submit(struct qemu_paiocb *aiocb)
{
+ struct work_item *work;
+
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);
+
+ work = async_work_init(&aio_request_list, aio_thread, aiocb);
+ aiocb->work = work;
+ qemu_async_submit(&aio_request_list, work);
}
static ssize_t qemu_paio_return(struct qemu_paiocb *aiocb)
{
ssize_t ret;
- mutex_lock(&lock);
ret = aiocb->ret;
- mutex_unlock(&lock);
-
return ret;
}
@@ -535,14 +449,14 @@ static void paio_cancel(BlockDriverAIOCB *blockacb)
struct qemu_paiocb *acb = (struct qemu_paiocb *)blockacb;
int active = 0;
- mutex_lock(&lock);
if (!acb->active) {
- QTAILQ_REMOVE(&request_list, acb, node);
- acb->ret = -ECANCELED;
+ if (!qemu_async_cancel_work(&aio_request_list, acb->work))
+ acb->ret = -ECANCELED;
+ else
+ active = 1;
} else if (acb->ret == -EINPROGRESS) {
active = 1;
}
- mutex_unlock(&lock);
if (active) {
/* fail safe: if the aio could not be canceled, we wait for
@@ -615,7 +529,6 @@ int paio_init(void)
struct sigaction act;
PosixAioState *s;
int fds[2];
- int ret;
if (posix_aio_state)
return 0;
@@ -642,16 +555,7 @@ int paio_init(void)
qemu_aio_set_fd_handler(s->rfd, posix_aio_read, NULL, posix_aio_flush,
posix_aio_process_queue, 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);
-
posix_aio_state = s;
+ async_queue_init(&aio_request_list, max_threads, max_threads);
return 0;
}
