From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: gfn_lock() seems useless.
Date: Wed, 3 Feb 2016 10:01:05 -0500
Message-ID: <20160203150105.GA20732@char.us.oracle.com>
References: <0259E1C966E8C54AA93AA2B1240828E650F4940E@szxema507-mbs.china.huawei.com>
	<56B0E6CD02000078000CDA09@prv-mh.provo.novell.com>
	<CADzFZPtJgb9nB+cKh+Jb6AMG51YPsY32hYSyVuwU4XV3Ue_k5w@mail.gmail.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: <CADzFZPtJgb9nB+cKh+Jb6AMG51YPsY32hYSyVuwU4XV3Ue_k5w@mail.gmail.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: Andres Lagar Cavilla <andres@lagarcavilla.org>
Cc: "Zhangbo (Oscar)" <oscar.zhangbo@huawei.com>, "Huangpeng (Peter)" <peter.huangpeng@huawei.com>, "xen-devel@lists.xen.org" <xen-devel@lists.xen.org>, "Herongguang (Stephen)" <herongguang.he@huawei.com>, Linqiangmin <linqiangmin@huawei.com>, Jan Beulich <JBeulich@suse.com>, "Wangyufei (James)" <james.wangyufei@huawei.com>
List-Id: xen-devel@lists.xenproject.org

On Tue, Feb 02, 2016 at 08:55:50PM -0800, Andres Lagar Cavilla wrote:
> At the time, I had a patch queue for splitting the p2m locking into a tree
> of per-2M locks. Very similar to Linux's split locks. I scaffolded the
> macros to allow for that expansion. Then, I got pulled onto other things.

Could you post/point folks to your patch queue?

Thanks.
> 
> Andres
> 
> On Tue, Feb 2, 2016 at 8:26 AM, Jan Beulich <JBeulich@suse.com> wrote:
> 
> > >>> On 02.02.16 at 07:54, <oscar.zhangbo@huawei.com> wrote:
> > > Hi all:
> > > In patch e1e40bccee7490a01ac7d1f759ec2bbafd3c7185, it says that"many
> > > routines can logically assert holding the p2m *FOR A SPECIFIC GFN.*" ,
> > > But I find out that it did nothing for locking a single gfn, in fact  it
> > > still locked the entire p2m list.
> > >
> > > -#define p2m_lock_recursive(p) mm_lock_recursive(p2m, &(p)->lock)
> > > +#define gfn_lock(p,g,o)       mm_lock_recursive(p2m, &(p)->lock)  //'g'
> > is not
> > > used. The entire p2m list is locked.
> > >
> > >
> > > Do we have any plan to lock a specific gfn?
> >
> > This indeed is a long term plan, but afaik no-one is currently
> > doing any work in that direction.
> >
> > Jan
> >
> >

> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel