Daniel McNeil wrote:

>I prefer getting the error on io_submit.
>  
>
I prefer getting the error on io_getevents().  The code that handles the 
output of io_getevents() already has to handle per-operation errors.  
The only thing user space can reasonably do with errors returned by 
io_submit() is to retry or assert.  Anything else would duplicate logic 
that already has to be in and is better handled by the code that handles 
the output io_getevents().

io_submit() should only return errors in cases where the caller is 
obviously buggy/malicious or in cases where it is not possible to 
generate an event.