Re: shared rings. rsp_cons, rsp_events, req_prod, req_events docs, charts, timelines?

[Daniel Stodden <daniel.stodden@citrix.com>]

On Mon, 2011-05-16 at 13:05 -0400, Konrad Rzeszutek Wilk wrote:
> The current ring implementation uses these values and then macros such
> as RING_HAS_UNCONSUMED_REQUESTS, FINAL_RING_CHECK, etc to determine whether
> to continue or how to control the flow. Looking way back in the history
> at c/s 8153 it used to have a 'server_is_sleeping' value to determine whether
> to kick the back (now called 'req_event'), and the 'rsp_event' (unchanged)
> to kick the frontend.
> 
> Anyhow, are there any diagrams or design docs documenting how these simple four
> shared values help to control the pipeline and interrupt generation? Or how
> they evolved over time to become what they are right now?

Iirc, I've known these headers since late xen 2.x versions and never saw
it done differently (i.e. req/rsp_event, and symmetrically).

Never saw dedicated documentation either, but found the header comments
and sources sufficient.

Do you just want documentation to point at, or is there something not
clear about them?

Daniel