Re: [Qemu-devel] [RFC PATCH v2 0/3] separate thread for VM migration

[shawn che]

Hi ,

I am studying KVM, but I have a question to ask.I wish someone can spare
time to help me.

What does the file "Assigned-dev.c" use for? I add some printk in the
funcitons in this file,but it seldom work.
Is it used for VT-d or others? can you give me some suggestions?

Thank you so much for your feedback...

[Qemu-devel] [RFC PATCH v2 0/3] separate thread for VM migration

[Umesh Deshpande]

Following patch deals with VCPU and iothread starvation during the migration of
a guest. Currently the iothread is responsible for performing the guest
migration. It holds qemu_mutex during the migration and doesn't allow VCPU to
enter the qemu mode and delays its return to the guest. The guest migration,
executed as an iohandler also delays the execution of other iohandlers.
In the following patch series,

The migration has been moved to a separate thread to
reduce the qemu_mutex contention and iohandler starvation.

Also current dirty bitmap is split into per memslot bitmap to reduce its size.

Umesh Deshpande (3):
  separate thread for VM migration
  fine grained qemu_mutex locking for migration
  per memslot dirty bitmap

 arch_init.c |   14 ++--
 buffered_file.c |   28 -
 buffered_file.h |4 +++
 cpu-all.h   |   40 ++--
 exec.c  |   38 +-
 migration.c |   60 --
 migration.h |3 ++
 savevm.c|   22 +---
 savevm.h|   29 ++
 xen-all.c   |6 +---
 10 files changed, 173 insertions(+), 71 deletions(-)
 create mode 100644 savevm.h

-- 
1.7.4.1