On 7/31/20 1:25 PM, Stefan Hajnoczi wrote: > On Fri, Jul 10, 2020 at 08:27:09PM +0300, Denis V. Lunev wrote: >> There are severe delays with IO requests processing if QEMU is running in >> virtual machine or over software defined storage. Such delays potentially >> results in unpredictable guest behavior. For example, guests over IDE or >> SATA drive could remount filesystem read-only if write is performed >> longer than 10 seconds. >> >> Such reports are very complex to process. Some good starting point for this >> seems quite reasonable. This patch provides one. It adds logging of such >> potentially dangerous long IO operations. >> >> Signed-off-by: Denis V. Lunev <[email protected]> >> CC: Vladimir Sementsov-Ogievskiy <[email protected]> >> CC: Kevin Wolf <[email protected]> >> CC: Max Reitz <[email protected]> > If I understand correctly this only reports completed I/Os, so if the > host hasn't given up on an I/O request yet then QEMU will not report it > is taking a long time. In the meantime the guest could start printing > timeout errors. > > I think this patch series is good as it is. In the future maybe a QMP > command that lists in-flight I/O requests would be nice. That helps > when troubleshooting I/Os that are hung. We could dump requests at block level, we do have proper lists, but the would be a little bit different.
Anyway, I __DO__ like this idea, I have missed this somehow :) Thank you for the suggestion, Den
