From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ian Campbell <ian.campbell@citrix.com>
Subject: Re: [PATCH] tools/libxc: Improve efficiency of
 xc_cpuid_apply_policy()
Date: Wed, 7 Oct 2015 12:52:29 +0100
Message-ID: <1444218749.1410.21.camel@citrix.com>
References: <1444050737-8437-1-git-send-email-andrew.cooper3@citrix.com>
	<20151006091457.GP29124@zion.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>
In-Reply-To: <20151006091457.GP29124@zion.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: Wei Liu <wei.liu2@citrix.com>, Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>, Xen-devel <xen-devel@lists.xen.org>
List-Id: xen-devel@lists.xenproject.org

On Tue, 2015-10-06 at 10:14 +0100, Wei Liu wrote:
> On Mon, Oct 05, 2015 at 02:12:17PM +0100, Andrew Cooper wrote:
> > Having the internals of xc_cpuid_policy() make hypercalls to collect
> > domain
> > information causes xc_cpuid_apply_policy() to be very inefficient.
> > 
> > Re-order operations to collect all information at once at the outermost
> > layer,
> > and pass a structure in to all cpuid policy generation functions.
> > 
> > This removes several hypercalls (4 from HVM, 3 from PV) for each of the
> > up-to 108 leaves processed.
> > 
> > No change in the eventual policy provided, although all the information
> > gathering how has (or has correct) error checking.
> > 
> > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> > ---
> > CC: Ian Campbell <Ian.Campbell@citrix.com>
> > CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
> > CC: Wei Liu <wei.liu2@citrix.com>
> 
> Acked-by: Wei Liu <wei.liu2@citrix.com>

Applied.

> > +    /* PV-only information. */
> > +    bool pv64;
> > +
> > +    /* HVM-only infomation. */

Typo fixed


> > +    bool pae;
> > +    bool nestedhvm;
> 
> I would have used union for these fields. But I don't want to bikeshed
> too much on this. Definitely not a blocker for this patch. :-)

Indeed.

Ian.