On Wed, Aug 31, 2022 at 12:06:37PM +0100, Richard W.M. Jones wrote:> On Wed, Aug 31, 2022 at 06:33:25PM +0800, Ming Lei wrote: > > On Wed, Aug 31, 2022 at 11:22:04AM +0100, Richard W.M. Jones wrote: > > > > > > After running those tests for an hour or two I got a nasty kernel > > > memory corruption issue in the test VM, see attached. > > > > >From the dmesg log, the direct issue is from zram. > > > > The userspace ublksrv shouldn't trigger this kind of issue, and the only > > related code is to discard IO pages if they are idle for enough time via > > madvise(MADV_DONTNEED). > > > > In the ublk driver side, we just pin and unpin pages, and it shouldn't > > be hard to verify if they work correctly . I will trace in that area. > > Except for pin & unpin pages, ublk driver doesn't play any other mm > > game. > > In case it's an unrelated bug in the very new RC2 kernel I've started > another test which just uses a local (virtio-scsi) disk, to see if I > observe the same thing or not.Maybe you should use one nbd disk, which has the closest code path with nbdublk. Thanks, Ming
Richard W.M. Jones
2022-Sep-01 11:14 UTC
[Libguestfs] [PATCH libnbd] ublk: Add new nbdublk program
On Thu, Sep 01, 2022 at 04:01:39PM +0800, Ming Lei wrote:> Maybe you should use one nbd disk, which has the closest code path > with nbdublk.Good idea - I have started a heavy test using nbd.ko as the backing. Let's see what happens after 12 hours or more. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com nbdkit - Flexible, fast NBD server with plugins https://gitlab.com/nbdkit/nbdkit