[Qemu-devel] About QEMU BQL and dirty log switch in Migration

[Yang Hongyang]

Hi all,

We found dirty log switch costs more then 13 seconds while migrating
a 4T memory guest, and dirty log switch is currently protected by QEMU
BQL. This causes guest freeze for a long time when switching dirty log on,
and the migration downtime is unacceptable.
Are there any chance to optimize the time cost for dirty log switch operation?
Or move the time consuming operation out of the QEMU BQL?

-- 
Thanks,
Yang