From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: [PATCH 6/6] xl: 'xl info' print outstanding claims
 if enabled (claim_mode=1 in xl.conf)
Date: Fri, 29 Mar 2013 09:31:14 -0400
Message-ID: <20130329133114.GF31356@phenom.dumpdata.com>
References: <1364417739-10121-1-git-send-email-konrad.wilk@oracle.com>
	<1364417739-10121-7-git-send-email-konrad.wilk@oracle.com>
	<20820.29717.491712.538567@mariner.uk.xensource.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
Content-Disposition: inline
In-Reply-To: <20820.29717.491712.538567@mariner.uk.xensource.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>, "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>, Ian Campbell <Ian.Campbell@citrix.com>
List-Id: xen-devel@lists.xenproject.org

On Thu, Mar 28, 2013 at 04:47:17PM +0000, Ian Jackson wrote:
> Konrad Rzeszutek Wilk writes ("[PATCH 6/6] xl: 'xl info' print outstanding claims if enabled (claim_mode=1 in xl.conf)"):
> > This patch provides the value of the currently outstanding pages
> > claimed for all domains. This is a total global value that influences
> > the hypervisors' MM system.
> > 
> > When a claim call is done, a reservation for a specific amount of pages
> > is set and also a global value is incremented. This global value is then
> > reduced as the domain's memory is populated and eventually reaches zero.
> > The toolstack can also choose to set the domain's claim to zero which
> > cancels the reservation and decrements the global value by the amount
> > of claim that has not been satisfied.
> 
> This description is good, but something like it needs to be in the
> documentation.

The documentation being xl.conf right? It already is in xen.conf thanks
to the first patch.

> 
> > +uint64_t libxl_get_claiminfo(libxl_ctx *ctx)
> > +{
> > +    long l;
> > +
> > +    l = xc_domain_get_outstanding_pages(ctx->xch);
> > +    if (l < 0)
> > +        return l;
> > +
> > +    /* In MB */
> > +    return (l >> 8);
> > +}
> 
> libxl functions should return libxl error values, not whatever you got
> from libxc.

OK.
> 
> I don't mind very much what the libxc function returns but the libxl
> function needs to handle the error properly.  See Ian C's comments on
> the previous version of this patch.

OK, I probably missed something in his reply - the errno that we would
mostly get (-ENOSYS) is neutered, so that it would not pipe up to
libxl (first patch).

However, there is of course nothing stopping from adding better error
handling in this code in case we get -EPERM or such. Patch shortly coming up.

> 
> Thanks,
> Ian.