Re: [dm-devel] RFC: multipath IO multiplex

[Alasdair G Kergon <agk redhat com>]

On Mon, Nov 08, 2010 at 01:19:41PM +0100, Lars Marowsky-Bree wrote:
> I wonder how other latency-sensitive IO handles multipath? Maybe they
> just haven't noticed yet they'd like a facility like this? ;-)
 
As usual, it's the lack of a cancellation interface for incomplete I/O
that seems to make the kernel-side option troublesome: we still have
to wait for timeouts.  Do we prevent more than one I/O being sent
in this mode, given that any other alternative would have races?

Alasdair