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block: avoid SIGUSR2

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Now that iothread is always compiled sending a signal seems only an
additional step. This patch also avoid writing to two pipe (one from signal
and one in qemu_service_io).

Work with kvm enabled or disabled. strace output is more readable (less syscalls).

[ kwolf: Merged build fix by Paolo Bonzini ]

Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Frediano Ziglio 2011-09-19 16:37:13 +02:00 committed by Kevin Wolf
parent bd5da23265
commit e1d3b25499
2 changed files with 9 additions and 29 deletions
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5
cpus.c
View File

@ -380,11 +380,6 @@ static int qemu_signal_init(void)
int sigfd; int sigfd;
sigset_t set; sigset_t set;
/* SIGUSR2 used by posix-aio-compat.c */
sigemptyset(&set);
sigaddset(&set, SIGUSR2);
pthread_sigmask(SIG_UNBLOCK, &set, NULL);
/* /*
* SIG_IPI must be blocked in the main thread and must not be caught * SIG_IPI must be blocked in the main thread and must not be caught
* by sigwait() in the signal thread. Otherwise, the cpu thread will * by sigwait() in the signal thread. Otherwise, the cpu thread will

33
posix-aio-compat.c
View File

@ -42,7 +42,6 @@ struct qemu_paiocb {
int aio_niov; int aio_niov;
size_t aio_nbytes; size_t aio_nbytes;
#define aio_ioctl_cmd aio_nbytes /* for QEMU_AIO_IOCTL */ #define aio_ioctl_cmd aio_nbytes /* for QEMU_AIO_IOCTL */
int ev_signo;
off_t aio_offset; off_t aio_offset;
QTAILQ_ENTRY(qemu_paiocb) node; QTAILQ_ENTRY(qemu_paiocb) node;
@ -308,12 +307,10 @@ static ssize_t handle_aiocb_rw(struct qemu_paiocb *aiocb)
return nbytes; return nbytes;
} }
static void posix_aio_notify_event(void);
static void *aio_thread(void *unused) static void *aio_thread(void *unused)
{ {
pid_t pid;
pid = getpid();
mutex_lock(&lock); mutex_lock(&lock);
pending_threads--; pending_threads--;
mutex_unlock(&lock); mutex_unlock(&lock);
@ -380,7 +377,7 @@ static void *aio_thread(void *unused)
aiocb->ret = ret; aiocb->ret = ret;
mutex_unlock(&lock); mutex_unlock(&lock);
if (kill(pid, aiocb->ev_signo)) die("kill failed"); posix_aio_notify_event();
} }
cur_threads--; cur_threads--;
@ -547,18 +544,14 @@ static int posix_aio_flush(void *opaque)
static PosixAioState *posix_aio_state; static PosixAioState *posix_aio_state;
static void aio_signal_handler(int signum) static void posix_aio_notify_event(void)
{ {
if (posix_aio_state) { char byte = 0;
char byte = 0; ssize_t ret;
ssize_t ret;
ret = write(posix_aio_state->wfd, &byte, sizeof(byte)); ret = write(posix_aio_state->wfd, &byte, sizeof(byte));
if (ret < 0 && errno != EAGAIN) if (ret < 0 && errno != EAGAIN)
die("write()"); die("write()");
}
qemu_service_io();
} }
static void paio_remove(struct qemu_paiocb *acb) static void paio_remove(struct qemu_paiocb *acb)
@ -622,7 +615,6 @@ BlockDriverAIOCB *paio_submit(BlockDriverState *bs, int fd,
return NULL; return NULL;
acb->aio_type = type; acb->aio_type = type;
acb->aio_fildes = fd; acb->aio_fildes = fd;
acb->ev_signo = SIGUSR2;
if (qiov) { if (qiov) {
acb->aio_iov = qiov->iov; acb->aio_iov = qiov->iov;
@ -650,7 +642,6 @@ BlockDriverAIOCB *paio_ioctl(BlockDriverState *bs, int fd,
return NULL; return NULL;
acb->aio_type = QEMU_AIO_IOCTL; acb->aio_type = QEMU_AIO_IOCTL;
acb->aio_fildes = fd; acb->aio_fildes = fd;
acb->ev_signo = SIGUSR2;
acb->aio_offset = 0; acb->aio_offset = 0;
acb->aio_ioctl_buf = buf; acb->aio_ioctl_buf = buf;
acb->aio_ioctl_cmd = req; acb->aio_ioctl_cmd = req;
@ -664,7 +655,6 @@ BlockDriverAIOCB *paio_ioctl(BlockDriverState *bs, int fd,
int paio_init(void) int paio_init(void)
{ {
struct sigaction act;
PosixAioState *s; PosixAioState *s;
int fds[2]; int fds[2];
int ret; int ret;
@ -674,11 +664,6 @@ int paio_init(void)
s = g_malloc(sizeof(PosixAioState)); s = g_malloc(sizeof(PosixAioState));
sigfillset(&act.sa_mask);
act.sa_flags = 0; /* do not restart syscalls to interrupt select() */
act.sa_handler = aio_signal_handler;
sigaction(SIGUSR2, &act, NULL);
s->first_aio = NULL; s->first_aio = NULL;
if (qemu_pipe(fds) == -1) { if (qemu_pipe(fds) == -1) {
fprintf(stderr, "failed to create pipe\n"); fprintf(stderr, "failed to create pipe\n");