On 2/11/21 11:40 PM, Eric Blake wrote: > On 2/11/21 8:26 AM, Philippe Mathieu-Daudé wrote: >> We are going to switch the 'null-co' default 'read-zeroes' value >> from FALSE to TRUE in the next commit. First explicit the FALSE >> value when it is not set. > > Grammar suggestion, along with a suggestion for an additional sentence > to make the intent of this commit clearer: > > As a first step, request an explicit FALSE value rather than relying on > the defaults. This is intended to be a purely mechanical adjustment for > no performance behavior in the tests; later patches may then flip or > elide the explicit choice for tests where performance does not matter. > >> >> Suggested-by: Eric Blake <ebl...@redhat.com> >> Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com> >> --- >> - Missing: 056 & 155. I couldn't figure out the proper syntax, >> any help welcomed... > > 056 - looks like just one line: > self.vm = > iotests.VM().add_drive_raw("file=blkdebug::null-co://,id=drive0,align=65536,driver=blkdebug") > > the best way to add it here would be rewriting that line to use blockdev > syntax rather than blkdebug: URI syntax. The other question is whether > it is a noticeable time difference when the default is flipped in 2/2. > > 155 - looks like several uses such as: > > class TestBlockdevMirrorForcedBacking(MirrorBaseClass): > cmd = 'blockdev-mirror' > existing = True > target_backing = None > target_blockdev_backing = { 'driver': 'null-co' } > target_real_backing = 'null-co://' > > >> - I'm unsure about 162, this doesn't seem to use the null-co >> driver but rather testing global syntax. > > Concur; I don't see any reason to worry about this one (but mentioning > it in the commit message can't hurt in case someone asks later) > > # blkdebug expects all of its arguments to be strings, but its > # bdrv_refresh_filename() implementation should not assume that they > have been > # passed as strings in the original options QDict. > # So this should emit blkdebug:42:null-co:// as the filename: > touch 42 > $QEMU_IMG info 'json:{"driver": "blkdebug", "config": 42, > "image.driver": "null-co"}' \ > > >> --- >> docs/devel/testing.rst | 14 +++++++------- >> tests/qtest/fuzz/generic_fuzz_configs.h | 11 ++++++----- >> tests/test-bdrv-drain.c | 10 ++++++++-- >> tests/acceptance/virtio_check_params.py | 2 +- >> tests/perf/block/qcow2/convert-blockstatus | 6 +++--- >> tests/qemu-iotests/040 | 2 +- > > You did a pretty good hunt for culprits! > >> tests/qemu-iotests/041 | 12 ++++++++---- >> tests/qemu-iotests/051 | 2 +- >> tests/qemu-iotests/051.out | 2 +- >> tests/qemu-iotests/051.pc.out | 4 ++-- > > and for the fallout to the iotests. > > I did not audit for which tests are easy candidates for dropping the > explicit read-zeroes=false (that is, where the extra time in allowing > the flipped default doesn't penalize the test), but am okay giving this > patch: > > Reviewed-by: Eric Blake <ebl...@redhat.com>
Thanks for your help. I'll address your comments and respin. Regards, Phil.