On Thu, 29 Mar 2018 12:03:42 +0200 Christian Borntraeger <borntrae...@de.ibm.com> wrote:
> On 03/29/2018 11:37 AM, Thomas Huth wrote: > > The current timeout is set to only three seconds - and considering that > > vring_wait_reply() or rather get_second() is not doing any rounding, > > the real timeout is likely rather 2 seconds in most cases. When the > > host is really badly loaded and we run the guest in TCG mode instead > > of KVM, it's possible that we hit this timeout by mistake. So let's > > increase the timeout to 30 seconds instead to ease this situation (30 > > seconds is also the timeout that is used by the Linux SCSI subsystem > > for example, so this seems to be a sane value for block IO timeout). > > I have never seen this, but cant this also with KVM (e.g. host paging > and the swap disk is busy for some seconds). It's probably less likely, but I don't see why not. 30s sounds like a more forgiving value. > > Wouldnt it also qualify for 2.12? I can queue it (and a bios rebuild) to s390-fixes, it's certainly reasonable. Else, Reviewed-by: Cornelia Huck <coh...@redhat.com> > > > > > Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1549079 > > Signed-off-by: Thomas Huth <th...@redhat.com> > > --- > > pc-bios/s390-ccw/virtio.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c > > index 817e7f5..cdb66f4 100644 > > --- a/pc-bios/s390-ccw/virtio.c > > +++ b/pc-bios/s390-ccw/virtio.c > > @@ -14,7 +14,7 @@ > > #include "virtio-scsi.h" > > #include "bswap.h" > > > > -#define VRING_WAIT_REPLY_TIMEOUT 3 > > +#define VRING_WAIT_REPLY_TIMEOUT 30 > > > > static VRing block[VIRTIO_MAX_VQS]; > > static char ring_area[VIRTIO_RING_SIZE * VIRTIO_MAX_VQS] > > >
