Re: [Qemu-devel] linux-user crashing in multi-threaded programs

[Alexander Graf]

On 21.11.2011, at 10:59, Peter Maydell wrote:

> On 21 November 2011 09:55, Alexander Graf <address@hidden> wrote:
>> On 21.11.2011, at 09:54, Peter Maydell wrote:
>>> I think I sent you my work-in-progress patch, didn't I?
>> 
>> I know that we talked about it. But I can't find it. That doesn't
>> mean that you didn't send it, but either way I'd really like to see
>> your patch somewhere where it can be found by more people than just
>> me. How about the bug report? :)
> 
> Good idea -- I'll attach it there today.
> 
>> There's also always the chance of doing tricks like I did in my patch
>> tonight, so you could do the unlinking code in single-threaded
>> applications and switch to the more expensive flag check in
>> multi-threaded ones.
> 
> You can hit this bug even single-threaded or in system mode:
> it's just that aggressively multi-threaded user apps are the
> easiest way to trigger it. So I don't think we can ever use
> the tb-unlinking code safely.

Not sure I understand. I thought it's a race between multiple threads trying to 
chain/unchain TBs at the same time? How can that happen in system or 
single-threaded mode?

Alex