From mboxrd@z Thu Jan  1 00:00:00 1970
From: Olaf Hering <olaf@aepfle.de>
Subject: Re: [PATCH 1 of 4] Improve ring management for memory
	events
Date: Wed, 23 Nov 2011 19:35:11 +0100
Message-ID: <20111123183511.GA26144@aepfle.de>
References: <patchbomb.1321307910@xdev.gridcentric.ca>
	<ee909e5a9d8555d7dd4d.1321307911@xdev.gridcentric.ca>
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To: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Cc: andres@gridcentric.ca, xen-devel@lists.xensource.com, tim@xen.org, keir.xen@gmail.com, adin@gridcentric.ca
List-Id: xen-devel@lists.xenproject.org

On Mon, Nov 14, Andres Lagar-Cavilla wrote:

I will do a more complete review later, a few comments below.


> +    free_requests = RING_FREE_REQUESTS(&med->front_ring);
> +    if ( unlikely(free_requests < d->max_vcpus) )
> +    {
> +        /* This may happen during normal operation (hopefully not often). */
> +        gdprintk(XENLOG_INFO, "mem_event request slots for domain %d: %d\n",
> +                               d->domain_id, free_requests);

What is the purpose of this printk? The ring can and does fillup quickly
with paging.


> +    if ( mem_event_ring_free(d, med) == 0 )
> +    {
> +        /* This *may* happen, but only when foreign mappings generate events. */
> +        gdprintk(XENLOG_WARNING, "possible lost mem_event for domain %d\n",
> +                                 d->domain_id);

This printk is not needed, callers have to try again.

Olaf