Re: [dm-devel] [PATCH 4/5] aio: vmap ringbuffer

[Kent Overstreet <koverstreet google com>]

On Tue, Oct 09, 2012 at 05:36:26PM -0700, Zach Brown wrote:
> > The only situation you have to worry about is when the ringbuffer fills
> > up and stuff goes on the list, and then completions completely stop -
> > this should be a rare enough situation that maybe we could just hack
> > around it with a timer that gets flipped on when the list isn't empty.
> 
> Right.  And this is when we hopefully realize that we're adding overhead
> and complexity (how long's the timer?  always fire it?  MAKE IT STOP)
> and are actually making the system worse, not better.

Can still prototype it, and if it's that ugly... I throw away code all
the time :P

> > Also, for this to be an issue at all, _all_ the reaping would have to be
> > done from userspace - since existing libaio doesn't do that, there may
> > not be any code out there which triggers it.
> 
> And there may be.  We default to not breaking interfaces.  Seriously.

All the more reason to think about it now so we don't screw up the next
interfaces :)