On 07/07/20 07:33, Markus Armbruster wrote: > Philippe Mathieu-Daudé <phi...@redhat.com> writes: > >> On 7/7/20 6:45 AM, Thomas Huth wrote: >>> 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 <arm...@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! > > That's surprising.
It's a bit surprising indeed, but on the other hand using g_queue_insert_sorted results in a quadratic loop. It should probably be fixed by using g_queue_sort, or switching to g_list_prepend+g_list_sort. Paolo >> Argh, yesterday I reviewed again all the range except this patch... not >> sure why as looking at it now it is obvious. >> >>> 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? >> >> Suggestion: add a '-u' option for unsorted mode, to use in qtests. >> >> Humans want the new behavior (default: sorted). > > Last resort. > > I'll look into speeding up the sort first. > > Work-around: drop -m slow until we get this sorted (pardon the pun). >
