Re: [Qemu-devel] [PATCH v4 1/1] Make qemu_peek_buffer loop until it gets it's data

[陈梁]

> * ???? (address@hidden) wrote:
>> 
>>> * ???? (address@hidden) wrote:
>>>> 
>>>> ?? 2014??4??8????????10:29??Dr. David Alan Gilbert (git) <address@hidden> 
>>>> ??????
>>>> 
>>>>> From: "Dr. David Alan Gilbert" <address@hidden>
>>>>> 
>>>>> Make qemu_peek_buffer repeatedly call fill_buffer until it gets
>>>>> all the data it requires, or until there is an error.
>>>>> 
>>>>> At the moment, qemu_peek_buffer will try one qemu_fill_buffer if there
>>>>> isn't enough data waiting, however the kernel is entitled to return
>>>>> just a few bytes, and still leave qemu_peek_buffer with less bytes
>>>>> than it needed.  I've seen this fail in a dev world, and I think it
>>>>> could theoretically fail in the peeking of the subsection headers in
>>>>> the current world.
>>>> hmm, I also have got some errors(infrequently). Maybe It is one point.
>>>> Could you show some messages about the error?
>>> 
>>> I've only seen the errors in my visitor/ber world where I use the 
>>> peek_buffer
>>> a lot more; but the one place it is used in the existing code is in
>>> the code to check if we have the start of a subsection; if that goes wrong
>>> I'm not sure what error would be produced.
>>> 
>>> Dave
>> In my observation, error is more likely to happen if migration thread is 
>> blocked too long.
>> BTW, xbzrle and auto convergence are disable.
> 
> What error do you see?
> 
> Dave
It likes section id 1 load failed at dest side.
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK