From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: shared rings. rsp_cons, rsp_events, req_prod,
 req_events docs, charts, timelines?
Date: Mon, 16 May 2011 13:05:43 -0400
Message-ID: <20110516170543.GA28949@dumpdata.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Return-path: <xen-devel-bounces@lists.xensource.com>
Content-Disposition: inline
List-Unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xensource.com>
List-Help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-Subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
Sender: xen-devel-bounces@lists.xensource.com
Errors-To: xen-devel-bounces@lists.xensource.com
To: xen-devel@lists.xensource.com, Ian Campbell <Ian.Campbell@eu.citrix.com>, daniel.stodden@citrix.com, keir@xen.org, JBeulich@novell.com
List-Id: xen-devel@lists.xenproject.org

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?