Re: [Qemu-devel] [PATCH 1/8] tcg: Clean up direct block chaining data fields

[Paolo Bonzini]

On 29/03/2016 10:14, Paolo Bonzini wrote:
> 
> 
> On 29/03/2016 00:12, Richard Henderson wrote:
>>> There is also a case where a TB jumps to itself; it then appears twice
>>> in the list with different values in the low bits, such as this:
>>>
>>>      tb->jmp_list_first = tb | 0;
>>>       .--------------------'   |
>>>       |                .-------'
>>>      tb->jmp_list_next[0] = tb | 2;
>>
>> Of course, it begs the question of why TB would be in its own list, even
>> if it does jump to itself.  We only need the points-to list in order to
>> invalidate a TB and unlink it.  But if TB is being invalidated, we don't
>> need to reset the jump within TB itself.
> 
> Isn't it just because TB acts as the list head in the circular list?  Or
> am I misunderstanding you?

Ok, that was dumb. :) Understood it now.

Paolo