main: force enabling of I/O thread

Enabling the I/O thread by default seems like an important part of declaring
1.0.  Besides allowing true SMP support with KVM, the I/O thread means that the
TCG VCPU doesn't have to multiplex itself with the I/O dispatch routines which
currently requires a (racey) signal based alarm system.

I know there have been concerns about performance.  I think so far the ones that
have come up (virtio-net) are most likely due to secondary reasons like
decreased batching.

I think we ought to force enabling I/O thread early in 1.0 development and
commit to resolving any lingering issues.

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

1 files changed, 1 insertions, 1 deletions

diff --git a/kvm-all.c b/kvm-all.c
index 0ae2e2697e..fbb9ff3bef 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -479,7 +479,7 @@ static int kvm_check_many_ioeventfds(void)
      * Older kernels have a 6 device limit on the KVM io bus.  Find out so we
      * can avoid creating too many ioeventfds.
      */
-#if defined(CONFIG_EVENTFD) && defined(CONFIG_IOTHREAD)
+#if defined(CONFIG_EVENTFD)
     int ioeventfds[7];
     int i, ret = 0;
     for (i = 0; i < ARRAY_SIZE(ioeventfds); i++) {