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Re: [qemu-s390x] [PATCH for-2.13] pc-bios/s390-ccw: Increase virtio time
Re: [qemu-s390x] [PATCH for-2.13] pc-bios/s390-ccw: Increase virtio timeout to 30 seconds
Thu, 29 Mar 2018 12:03:42 +0200
Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0
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).
Wouldnt it also qualify for 2.12?
> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1549079
> Signed-off-by: Thomas Huth <address@hidden>
> 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]