Make sure to read siginfo from signalfd

Otherwise, we'll idle at 100% cpu.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5195 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
aliguori 2008-09-11 14:32:27 +00:00
parent da3d9c5b46
commit 2c41a5f9e3
1 changed files with 27 additions and 0 deletions

View File

@ -449,6 +449,30 @@ static void qemu_aio_poll(void *opaque)
{
RawAIOCB *acb, **pacb;
int ret;
size_t offset;
union {
struct qemu_signalfd_siginfo siginfo;
char buf[128];
} sig;
/* try to read from signalfd, don't freak out if we can't read anything */
offset = 0;
while (offset < 128) {
ssize_t len;
len = read(aio_sig_fd, sig.buf + offset, 128 - offset);
if (len == -1 && errno == EINTR)
continue;
if (len == -1 && errno == EAGAIN) {
/* there is no natural reason for this to happen,
* so we'll spin hard until we get everything just
* to be on the safe side. */
if (offset > 0)
continue;
}
offset += len;
}
for(;;) {
pacb = &first_aio;
@ -498,6 +522,9 @@ void qemu_aio_init(void)
sigprocmask(SIG_BLOCK, &mask, NULL);
aio_sig_fd = qemu_signalfd(&mask);
fcntl(aio_sig_fd, F_SETFL, O_NONBLOCK);
#if !defined(QEMU_IMG) && !defined(QEMU_NBD)
qemu_set_fd_handler2(aio_sig_fd, NULL, qemu_aio_poll, NULL, NULL);
#endif