Hi,
On Wed, May 31, 2023 at 11:41:33AM +0100, Nikos Nikoleris wrote:
> Hi,
>
> I noticed that in the latest master the psci_cpu_on_test fails randomly for
> both arm and arm64 with tcg.
>
> If I do:
>
> $> for i in `seq 1 100`; do ACCEL=tcg MAX_SMP=8 ./run_tests.sh psci; done |
> grep FAIL
>
> About 10 of the 100 runs fail for the arm and arm64 builds of the test. I
> had a look and I am not sure I understand why. When I run the test with kvm,
> I don't get any failures. Does anyone have an idea what could be causing
> this?
My first thought was that the PSCI CPU_OFF patches were to blame. But I
tested with kvm-unit-tests built from commit 17b2373401c4 ("arm: Replace
MAX_SMP probe loop in favor of reading directly") (first patch before that
series) and I am getting the same error on some runs (15 out of 100 the
only time I bothered counting):
$ ACCEL=tcg MAX_SMP=8 ./run_tests.sh psci
FAIL psci (4 tests, 1 unexpected failures)
$ cat logs/psci.log
timeout -k 1s --foreground 90s /usr/bin/qemu-system-aarch64 -nodefaults -machine virt -accel tcg -cpu cortex-a57 -device virtio-serial-device -device virtconsole,chardev=ctd -chardev testdev,id=ctd -device pci-testdev -display none -serial stdio -kernel arm/psci.flat -smp 8 # -initrd /tmp/tmp.xbOEu4nmXR
INFO: psci: PSCI version 1.1
PASS: psci: invalid-function
PASS: psci: affinity-info-on
PASS: psci: affinity-info-off
INFO: psci: got 2 CPU_ON success
FAIL: psci: cpu-on
SUMMARY: 4 tests, 1 unexpected failures
with qemu version:
$ qemu-system-aarch64 --version
QEMU emulator version 8.0.2
Copyright (c) 2003-2022 Fabrice Bellard and the QEMU Project developers
Since it doesn't happen with KVM, I would perhaps try with older versions of
qemu, in case there's some sort of inter-thread synchronization hiccup like
there was with KVM. Failing that, you could try bisecting the issue in
kvm-unit-tests.
Thanks,
Alex
>
> Thanks,
>
> Nikos
