Re: [Kiobuf-io-devel] RFC: Kernel mechanism: Compound event wait

Jens Axboe
2001-02-06T19:33:15Z

On Tue, Feb 06 2001, Ben LaHaise wrote:
> > > - make asynchronous io possible in the block layer. This is
> > > impossible with the current ll_rw_block scheme and io request
> > > plugging.
> >
> > why is it impossible?
>
> s/impossible/unpleasant/. ll_rw_blk blocks; it should be possible to have
> a non blocking variant that does all of the setup in the caller's context.
> Yes, I know that we can do it with a kernel thread, but that isn't as
> clean and it significantly penalises small ios (hint: databases issue
> *lots* of small random ios and a good chunk of large ios).

So make a non-blocking variant, not a big deal. Users of async I/O
know how to deal with resource limits anyway.

--
Jens Axboe