On 13/05/2021 20:47, John Snow wrote:
On 4/14/21 1:03 PM, Emanuele Giuseppe Esposito wrote:
As with gdbserver, valgrind delays the test execution, so
the default QMP socket timeout timeout too soon.
Signed-off-by: Emanuele Giuseppe Esposito <eespo...@redhat.com>
---
python/qemu/machine.py | 2 +-
tests/qemu-iotests/iotests.py | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/python/qemu/machine.py b/python/qemu/machine.py
index d6142271c2..dce96e1858 100644
--- a/python/qemu/machine.py
+++ b/python/qemu/machine.py
@@ -410,7 +410,7 @@ def _launch(self) -> None:
shell=False,
close_fds=False)
- if 'gdbserver' in self._wrapper:
+ if 'gdbserver' in self._wrapper or 'valgrind' in self._wrapper:
This approaches me suggesting that we just change __init__ to accept a
parameter that lets the caller decide what kind of timeout(s) they find
acceptable. They know more about what they're trying to run than we do.
Certainly after launch occurs, the user is free to just grab the qmp
object and tinker around with the timeouts, but that does not allow us
to change the timeout(s) for accept itself.
D'oh.
(Spilled milk: It was probably a mistake to make the default launch
behavior here have a timeout of 15 seconds. That logic likely belongs to
the iotests implementation. The default here probably ought to indeed be
"wait forever".)
In the here and now ... would it be acceptable to change the launch()
method to add a timeout parameter? It's still a little awkward, because
conceptually it's a timeout for just QMP and not for the actual duration
of the entire launch process.
But, I guess, it's *closer* to the truth.
If you wanted to route it that way, I take back what I said about not
wanting to pass around variables to event loop hooks.
If we defined the timeout as something that applies exclusively to the
launching process, then it'd be appropriate to route that to the
launch-related functions ... and subclasses would have to be adjusted to
be made aware that they're expected to operate within those parameters,
which is good.
Sorry for my waffling back and forth on this. Let me know what the
actual requirements are if you figure out which timeouts you need /
don't need and I'll give you some review priority.
Uhm.. I am getting a little bit confused on what to do too :)
So the current plan I have for _qmp_timer is:
- As Max suggested, move it in __init__ and check there for the wrapper
contents. If we need to block forever (gdb, valgrind), we set it to
None. Otherwise to 15 seconds. I think setting it always to None is not
ideal, because if you are testing something that deadlocks (see my
attempts to remove/add locks in QEMU multiqueue) and the socket is set
to block forever, you don't know if the test is super slow or it just
deadlocked.
Well, one can argue that in both cases this is not the expected
behavior, but I think having an upper bound on each QMP command
execution would be good.
- pass _qmp_timer directly to self._qmp.accept() in _post launch,
leaving _launch() intact. I think this makes sense because as you also
mentioned, changing _post_launch() into taking a parameter requires
changing also all subclasses and pass values around.
Any opinion on this is very welcome.
Spoiler alert I haven't tested these changes yet, but I am positive that
there shouldn't be any problem. (Last famous words)
Emanuele
If you attack this series again, can you please split out the python/*
patches into its own little series and CC me?
--js
self._qmp_timer = None
self._post_launch()
diff --git a/tests/qemu-iotests/iotests.py
b/tests/qemu-iotests/iotests.py
index a2e8604674..94597433fa 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -489,7 +489,7 @@ def log(msg: Msg,
class Timeout:
def __init__(self, seconds, errmsg="Timeout"):
- if qemu_gdb:
+ if qemu_gdb or qemu_valgrind:
self.seconds = 3000
else:
self.seconds = seconds
@@ -700,7 +700,7 @@ def qmp_to_opts(self, obj):
return ','.join(output_list)
def get_qmp_events(self, wait: bool = False) -> List[QMPMessage]:
- if qemu_gdb:
+ if qemu_gdb or qemu_valgrind:
wait = 0.0
return super().get_qmp_events(wait=wait)
