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23.07.2019, 16:42, "Yury Kotov" <yury-ko...@yandex-team.ru>:
> Hi,
>
> V4:
> * The test was simplified to prevent false fails.
>
> V3:
> * Rebase fixes (migrate_set_parameter -> migrate_set_parameter_int)
>
> V2:
> * Added a test
> * Fixed qemu_cond_timedwait for qsp
>
> I wrote a test for migration auto converge and found out a strange thing:
> 1. Enable auto converge
> 2. Set max-bandwidth 1Gb/s
> 3. Set downtime-limit 1ms
> 4. Run standard test (just writes a byte per page)
> 5. Wait for converge
> 6. It's converged with 99% throttle percentage
> 7. The result downtime was about 300-600ms <<<<
>
> It's much higher than expected 1ms. I figured out that cpu_throttle_thread()
> function sleeps for 100ms+ for high throttle percentage (>=95%) in VCPU
> thread.
> And it sleeps even after a cpu kick.
>
> Fixed it by using timedwait for ms part of sleep.
> E.g timedwait(halt_cond, 1ms) + usleep(500).
>
> Regards,
> Yury
>
> Yury Kotov (3):
> qemu-thread: Add qemu_cond_timedwait
> cpus: Fix throttling during vm_stop
> tests/migration: Add a test for auto converge
>
> cpus.c | 27 +++++++---
> include/qemu/thread.h | 18 +++++++
> tests/migration-test.c | 103 ++++++++++++++++++++++++++++++++++-----
> util/qemu-thread-posix.c | 40 ++++++++++-----
> util/qemu-thread-win32.c | 16 ++++++
> util/qsp.c | 18 +++++++
> 6 files changed, 191 insertions(+), 31 deletions(-)
>
> --
> 2.22.0
