Re: [PATCH v3 06/33] util/async: aio_co_schedule(): support reschedule in same ctx

[Paolo Bonzini]

On 14/05/21 19:27, Roman Kagan wrote:
> AFAICS your patch has basically the same effect as Vladimir's
> patch "util/async: aio_co_enter(): do aio_co_schedule in general case"
> (https://lore.kernel.org/qemu-devel/20210408140827.332915-4-vsementsov@virtuozzo.com/).
> That one was found to break e.g. aio=threads cases.  I guessed it
> implicitly relied upon aio_co_enter() acquiring the aio_context but we
> didn't dig further to pinpoint the exact scenario.

That one is much more intrusive, because it goes through a bottom half 
unnecessarily in the case of aio_co_wake being called from an I/O 
callback (or from another bottom half).  I'll test my patch with 
aio=threads.

Paolo