[openib-general] Re: [PATCH] (repost) sdp: replace mlock with get_user_pages

[Michael S. Tsirkin]

Quoting r. Roland Dreier <roland at topspin.com>:
> Subject: Re: [openib-general] Re: [PATCH] (repost) sdp: replace mlock with get_user_pages
> 
>     Libor>   Always call aio_complete() immediately when
>     Libor> iocb_complete() is called, and only spawn the work thread
>     Libor> to unlock the memory after the aio_complete() call. The
>     Libor> patch is below.

Libor, I dont think its a good idea - this will break other assumptions,
like the assumption that the task mm isnt destroyed before we unlock
the memory.

> Another alternative would be to always complete aios asynchronously,
> which should preserve the order.  I guess this would hurt latency for
> small ios...
> 
>  - R.
> 

To avoid hurting latency, lets count the number of outstanding
asynchronous AIOs, and if there are asynchronous AIOs complete
all of them asynchronously.

Does this make sense?


-- 
MST - Michael S. Tsirkin