Slow down with: 'Make "info qom-tree" show children sorted'

[Thomas Huth <thuth@redhat.com>]

On 27/05/2020 10.47, Markus Armbruster wrote:
> "info qom-tree" prints children in unstable order.  This is a pain
> when diffing output for different versions to find change.  Print it
> sorted.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  qom/qom-hmp-cmds.c | 24 ++++++++++++++++--------
>  1 file changed, 16 insertions(+), 8 deletions(-)

 Hi Markus,

this patch causes a slow down of the qtests which becomes quite massive
when e.g. using the ppc64 and thourough testing. When I'm running

QTEST_QEMU_BINARY="ppc64-softmmu/qemu-system-ppc64" time \
./tests/qtest/device-introspect-test -m slow | tail -n 10

the test runs for ca. 6m40s here before the patch got applied, and for
mor than 20 minutes after the patch got applied!

This causes our gitlab CI to constantly fail since the patch got merged,
since the testing time now exceeds the 1h time limit:

 https://gitlab.com/qemu-project/qemu/-/pipelines/156767175

Sure, we can work around that problem in the CI (Alex has already a
patch queued), but still, is there something you could do about this
massive slowdown?

 Thanks,
  Thomas