From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH v2 2/2] libvchan: replace munmap with correct xc_gntshr_munmap Date: Fri, 10 May 2013 15:15:50 +0100 Message-ID: <518D0116.9040605@eu.citrix.com> References: <20130508040327.951AD329@duch.mimuw.edu.pl> <518A57ED.5030708@tycho.nsa.gov> <518A5C56.3000100@invisiblethingslab.com> <1368193596.27857.123.camel@zakaz.uk.xensource.com> <518CFC44.7060607@invisiblethingslab.com> <1368194889.27857.132.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1368194889.27857.132.camel@zakaz.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: Daniel De Graaf , Marek Marczykowski , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On 10/05/13 15:08, Ian Campbell wrote: > On Fri, 2013-05-10 at 14:55 +0100, Marek Marczykowski wrote: >> On 10.05.2013 15:46, Ian Campbell wrote: >>> On Wed, 2013-05-08 at 15:08 +0100, Marek Marczykowski wrote: >>>> On 08.05.2013 15:49, Daniel De Graaf wrote: >>>>> On 05/04/2013 06:10 PM, Marek Marczykowski wrote: >>>>>> On linux it will end up in munmap anyway, but do not assume any >>>>>> particular xc_gntshr_munmap implementation details. >>>>>> >>>>>> Signed-off-by: Marek Marczykowski >>>>> On a client, this ends up using xc_gntshr_munmap to unmap pages that >>>>> were mapped with xc_gnttab_map_* instead of using xc_gnttab_unmam >>>>> >>>>> George: unless there is another OS besides Linux that implements the >>>>> xc_gntshr_* interfaces (I found none from a grep of the source), this >>>>> is just code clean-up and so could be postponed to 4.4. >>>> This is actually prerequirement for libvchan for mini-os (already posted v1, >>>> working on v2). But as mini-os libvchan isn't targeted for 4.3, this one also >>>> can wait. >>> Is the first patch "libxc: fix xc_gntshr_munmap semantic" also included >>> in this assessment? >>> >>> Message-Id: <20130508040327.91296310@duch.mimuw.edu.pl> >> As long as libxenvchan is the only (at least I'm aware of) user of >> xc_gntshr_munmap - probably yes. But IMO it's better to fix xc_gntshr_munmap >> sooner than later, to minimize changes in code that uses it (if someone will >> start to use it before 4.4 release). > I'm not sure if you are arguing for or against putting that fix into > 4.3? I read this as, "We should make the interface more useful in case someone decides to use it after 4.3 comes out but before 4.4 comes out." To which my response was, if this is in libxc, people shouldn't be linking against it anyway. -George