Re: [Qemu-devel] [PATCH 20/41] migration: run pending/iterate callbacks out of big lock

[Juan Quintela]

Paolo Bonzini <address@hidden> wrote:
> This makes it possible to do blocking writes directly to the socket,
> with no buffer in the middle.  For RAM, only the migration_bitmap_sync()
> call needs the iothread lock.  For block migration, it is needed by
> the block layer (including bdrv_drain_all and dirty bitmap access),
> but because some code is shared between iterate and complete, all of
> mig_save_device_dirty is run with the lock taken.
>
> In the savevm case, the iterate callback runs within the big lock.
> This is annoying because it complicates the rules.  Luckily we do not
> need to do anything about it: the RAM iterate callback does not need
> the iothread lock, and block migration never runs during savevm.
>
> Signed-off-by: Paolo Bonzini <address@hidden>

Reviewed-by: Juan Quintela <address@hidden>