From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Magnus Damm" Date: Thu, 28 Sep 2006 12:34:20 +0000 Subject: Re: [Xen-ia64-devel] Re: ia64 kexec: xen -> linux Message-Id: List-Id: References: <200609271152.12393.Tristan.Gingold@bull.net> In-Reply-To: <200609271152.12393.Tristan.Gingold@bull.net> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: linux-ia64@vger.kernel.org On 9/28/06, Tristan Gingold wrote: > Le Jeudi 28 Septembre 2006 03:27, Horms a =E9crit : > > On Wed, Sep 27, 2006 at 11:52:12AM +0200, Tristan Gingold wrote: > > > Linux and xen call efi in real mode if set_virtual_address_map fails. > > > You may add an option in both xen and linux to force calling efi in r= eal > > > mode. This should be really simple and you will be able to make progr= ess. > > > > Great, I will test this out and see how it goes. > > > > > The only possible drawback is performance. > > > > What kind of performance issues would you expect? > Making EFI calls in physical mode is slower: Linux must switch from and to > virtual mode. > > However EFI calls are very unfrequent so the impact should be almost nul. This makes me wonder - is it really worth having two code paths in that cas= e? / magnus