From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerd Hoffmann Subject: Re: using PageForeign for pte allocation vs. shortcutting __pte_free_tlb() Date: Tue, 09 Jan 2007 12:11:42 +0100 Message-ID: <45A3786E.8090309@suse.de> References: <45A37AC3.76E4.0078.0@novell.com> <45A373A9.70304@suse.de> <45A3836D.76E4.0078.0@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <45A3836D.76E4.0078.0@novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jan Beulich Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Jan Beulich wrote: >>>> Gerd Hoffmann 09.01.07 11:51 >>> >> Jan Beulich wrote: >>> In the course of trying to get CONFIG_HIGHPTE to work I stumbled across this >>> inconsistency between i386 and x86-64 Linux: i386 uses SetPageForeign() in >>> (one the non-highpte) case of pte_alloc_one(), and leaves intact native's >>> definition of __pte_free_tlb(), whereas x86-64 doesn't use the former but >>> shortcuts the latter to just invoke pte_free(). Obviously it would be nice for >>> these two to be consistent, >> x86-64 has no HIGHMEM zone, thus CONFIG_HIGHPTE has no effect (I'm >> surprised it exists in the first place ...). > > Of course (and no, such a config option doesn't exist for x86-64), but what > relation does this have to the question asked? guess (not having looked at the code at all) i386 does that because it needs disturgish high and non-high ptes, whereas x86-64 simply has no need for that, so I don't see the point in trying to make them consistent ... cheers, Gerd -- Gerd Hoffmann