Comment 14 for bug 1769189

Could this affect virtio-scsi? I'm not so sure since it's not perfectly reliable to reproduce, but v2.12.0 was hanging for me for a few minutes at a time with virtio-scsi cache=writeback showing 100% disk util%. I never had issues booting up, and didn't try SATA. v2.11.1 was fine.

My first attempt to bisect didn't turn out right... had some false positives I guess. The 2nd attempt (telling git the bads from first try) got to 89e46eb477113550485bc24264d249de9fd1260a as latest good (which is 4 commits *after* the bisect by John Snow) and 7273db9d28d5e1b7a6c202a5054861c1f0bcc446 as bad.

But testing with this patch, it seems to work (or false positive still... after a bunch of usage). And so I didn't finish the bisect.