From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mukesh Rathor Subject: Re: [hybrid] : mmap pfn space... Date: Tue, 17 Apr 2012 18:20:09 -0700 Message-ID: <20120417182009.14219141@mantra.us.oracle.com> References: <20120323110144.4b2f1d45@mantra.us.oracle.com> <20120413184705.77b4d316@mantra.us.oracle.com> <1334585643.14560.199.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Stefano Stabellini Cc: "Xen-devel@lists.xensource.com" , Ian Campbell List-Id: xen-devel@lists.xenproject.org On Mon, 16 Apr 2012 17:22:14 +0100 Stefano Stabellini wrote: > On Mon, 16 Apr 2012, Ian Campbell wrote: > > > In a nutshell, I am still trying to figure how to allocate rsvd > > > pfn's for privcmd without writing a slab allocator. > > > > Can't you just use the core get_page function (or > > alloc_xenballooned_pages) and move the associated mfn aside > > temporarily (or not if using alloc_xenballooned_pages)? > > I think that is a good suggestion: if we are trying to get in > something that works but might not be the best solution, then using > alloc_xenballooned_pages to get some pages and then changing the p2m > is the best option: it wastes a non-trivial amount of memory in dom0 > but at least it is known to work well and it wouldn't be an "hack". > > Give a look at gntdev_alloc_map, gnttab_map_refs and m2p_add_override > for an example. Ok. I changed to using alloc_xenballooned_pages. In future, if we run into problems, we can look into alternatives. In past we've had problems with limits reached ballooing down. We run with small dom0. thanks, Mukesh