Re: [Qemu-devel] [PATCH 2/2] main: switch qemu_set_fd_handler to g_io_add_watch

[Avi Kivity <avi@redhat.com>]

On 09/04/2011 05:03 PM, Avi Kivity wrote:
> On 08/22/2011 04:12 PM, Anthony Liguori wrote:
>> This patch changes qemu_set_fd_handler to be implemented in terms of
>> g_io_add_watch().  The semantics are a bit different so some glue is 
>> required.
>>
>> qemu_set_fd_handler2 is much harder to convert because of its use of 
>> polling.
>>
>> The glib main loop has the major of advantage of having a proven 
>> thread safe
>> architecture.  By using the glib main loop instead of our own, it 
>> will allow us
>> to eventually introduce multiple I/O threads.
>>
>> I'm pretty sure that this will work on Win32, but I would appreciate 
>> some help
>> testing.  I think the semantics of g_io_channel_unix_new() are really 
>> just tied
>> to the notion of a "unix fd" and not necessarily unix itself.
>
> 'git bisect' fingered this as responsible for breaking 
> qcow2+cache=unsafe.  I think there's an off-by-one here and the guilty 
> patch is the one that switches the main loop, but that's just a guess.
>
> The symptoms are that a guest that is restarted (new qemu process) 
> after install doesn't make it through grub - some image data didn't 
> make it do disk.  With qcow2 and cache=unsafe that can easily happen 
> through exit notifiers not being run and the entire qcow2 metadata 
> being thrown out the window.  Running with raw+cache=unsafe works.
>

Upstream appears to work for me... strange.

-- 
error compiling committee.c: too many arguments to function