Re: [PATCH v2 14/20] iotests: 185: prepare for backup over block-copy

[Vladimir Sementsov-Ogievskiy]

23.07.2020 11:19, Max Reitz wrote:
> On 01.06.20 20:11, Vladimir Sementsov-Ogievskiy wrote:
> > The further change of moving backup to be a on block-copy call will
>
> -on?

one :)

> > make copying chunk-size and cluster-size a separate things. So, even
>
> s/a/two/
>
> > with 64k cluster sized qcow2 image, default chunk would be 1M.
> > 185 test however assumes, that with speed limited to 64K, one iteration
> > would result in offset=64K. It will change, as first iteration would
> > result in offset=1M independently of speed.
> >
> > So, let's explicitly specify, what test wants: set max-chunk to 64K, so
> > that one iteration is 64K. Note, that we don't need to limit
> > max-workers, as block-copy rate limitator will handle the situation and
>
> *limitator
>
> > wouldn't start new workers when speed limit is obviously reached.
> >
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> > ---
> >   tests/qemu-iotests/185     | 3 ++-
> >   tests/qemu-iotests/185.out | 2 +-
> >   2 files changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/tests/qemu-iotests/185 b/tests/qemu-iotests/185
> > index fd5e6ebe11..6afb3fc82f 100755
> > --- a/tests/qemu-iotests/185
> > +++ b/tests/qemu-iotests/185
> > @@ -182,7 +182,8 @@ _send_qemu_cmd $h \
> >                         'target': '$TEST_IMG.copy',
> >                         'format': '$IMGFMT',
> >                         'sync': 'full',
> > -                      'speed': 65536 } }" \
> > +                      'speed': 65536,
> > +                      'x-max-chunk': 65536 } }" \
>
> Out of curiosity, would it also suffice to disable copy offloading?

Note that x-max-chunk works even with copy offloading enabled, it sets maximum 
only for background copying, not for all operations.

> But anyway:
>
> Reviewed-by: Max Reitz <mreitz@redhat.com>
>
> >       "return"
> >   
> >   # If we don't sleep here 'quit' command races with disk I/O
> > diff --git a/tests/qemu-iotests/185.out b/tests/qemu-iotests/185.out
> > index ac5ab16bc8..5232647972 100644
> > --- a/tests/qemu-iotests/185.out
> > +++ b/tests/qemu-iotests/185.out
> > @@ -61,7 +61,7 @@ Formatting 'TEST_DIR/t.qcow2.copy', fmt=qcow2 size=67108864 
> > cluster_size=65536 l
> >   
> >   { 'execute': 'qmp_capabilities' }
> >   {"return": {}}
> > -{ 'execute': 'drive-backup', 'arguments': { 'device': 'disk', 'target': 
> > 'TEST_DIR/t.IMGFMT.copy', 'format': 'IMGFMT', 'sync': 'full', 'speed': 65536 } }
> > +{ 'execute': 'drive-backup', 'arguments': { 'device': 'disk', 'target': 
> > 'TEST_DIR/t.IMGFMT.copy', 'format': 'IMGFMT', 'sync': 'full', 'speed': 65536, 
> > 'x-max-chunk': 65536 } }
> >   Formatting 'TEST_DIR/t.qcow2.copy', fmt=qcow2 size=67108864 
> > cluster_size=65536 lazy_refcounts=off refcount_bits=16 compression_type=zlib
> >   {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": 
> > {"status": "created", "id": "disk"}}
> >   {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": 
> > {"status": "running", "id": "disk"}}


--
Best regards,
Vladimir