On Thu, Dec 11 2008, Andrea Arcangeli wrote: > On Thu, Dec 11, 2008 at 06:20:09PM +0100, Gerd Hoffmann wrote: > > Andrea Arcangeli wrote: > > > On Thu, Dec 11, 2008 at 05:11:08PM +0100, Gerd Hoffmann wrote: > > >> Yes. But kernel aio requires O_DIRECT, so aio users are affected > > >> nevertheless. > > > > > > Are you sure? It surely wasn't the case... > > > > Tons of docs say so, but might be they are wrong, I didn't check. > > I guess those tons of docs are just wrong then ;). I see no mention of > O_DIRECT in `man io_submit` at least... I seem to recall initially aio > only worked without O_DIRECT... ;). It's quite the opposite, O_DIRECT > works best with kernel aio, not the other way around. O_DIRECT > read/writes look very much like non-O_DIRECT seeking reads. For > seeking sync-reads kernel aio pays off as well as with O_DIRECT.
aio is only async with O_DIRECT, with buffered IO it's sync. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
