Re: [Qemu-devel] QEMU live block-migration

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Quoting Yaodong Yang (2013-07-07 09:55:06)
> Hello everyone,
>    I have a short question about the implementation of QEMU. When the qemu
>    perform the live block migration using "migrate -b tcp:...." command. Does
>    a new thread for migration created or not? I went through the code, only
>    find that this activity is triggered in the main loop (main_loop_wait(int

An outgoing non-blocking connection is triggered by
tcp_start_outgoing_migration, once the connection is completed the
tcp_wait_for_connect() callback is executed by the main loop.

>    nonblocking) function). I want to know is there a new dedicated thread
>    created for this migration task or not? If so, where in the code the new
>    thread created.

Within that callback there's a call to migrate_fd_connect(), which is where the
migration thread is created.

Incoming migration is still handled by the main loop's thread

>    Thanks!
>    Yaodong
>    --
>    Yaodong Yang
>    Computer Science and Engineering Department
>    University of Nebraska--Lincoln, 
>    Lincoln, NE, U.S.A.