From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mario Smarduch Date: Fri, 26 Sep 2003 15:41:13 +0000 Subject: Re: vhpt_miss handler question? Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: linux-ia64@vger.kernel.org Keith Owens wrote: > On Fri, 26 Sep 2003 09:43:55 -0500, > Mario Smarduch wrote: > >Some work I'm doing has taken me to the vhpt_miss > >handler. I've been looking at the following snippet just > >wondering what happens in the case where the present > >bit is 0 and p10,p11 predicates are not set anotherwords > >they retain their application values. Would this not > >cause an errant insertion if either p10 or p11 were > >true in the application prior to the VHPT handler? > > >(p7) tbit.nz.unc p10,p11=3Dr19,32 // is it an instruction > > tbit.xx.unc sets both predicates to 0 if the controlling predicate is > false. See the 'else' clause on page 3:229 of Document Number: > 245319-004 (ia64 Volume 3: Instruction Set Reference). I understand the unc sets bot predicates to 0. The question was regarding p7=FAlse, but it appears in that case a TLB entry with present bit set to 0 may be inserted which appears to be harmless (other then taking up a TC entry). Sorry for the noise :) - mario.