From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58866) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f1VJy-0006Qf-6y for qemu-devel@nongnu.org; Thu, 29 Mar 2018 07:02:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f1VJv-0007yR-5u for qemu-devel@nongnu.org; Thu, 29 Mar 2018 07:02:18 -0400 Date: Thu, 29 Mar 2018 13:02:06 +0200 From: Cornelia Huck Message-ID: <20180329130206.0b33b040.cohuck@redhat.com> In-Reply-To: <2103b547-66aa-d1f7-a504-cb6ef3672039@de.ibm.com> References: <1522316251-16399-1-git-send-email-thuth@redhat.com> <2103b547-66aa-d1f7-a504-cb6ef3672039@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH for-2.13] pc-bios/s390-ccw: Increase virtio timeout to 30 seconds List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christian Borntraeger Cc: Thomas Huth , qemu-s390x@nongnu.org, qemu-devel@nongnu.org, ldoktor@redhat.com On Thu, 29 Mar 2018 12:03:42 +0200 Christian Borntraeger 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 > > > > > Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1549079 > > Signed-off-by: Thomas Huth > > --- > > 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] > > >