From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 8 Jan 2008 04:31:03 +0100 From: Andi Kleen Subject: Re: [rfc][patch] mm: use a pte bit to flag normal pages Message-ID: <20080108033103.GH2998@bingen.suse.de> References: <20071221104701.GE28484@wotan.suse.de> <20080107044355.GA11222@wotan.suse.de> <20080107103028.GA9325@flint.arm.linux.org.uk> <6934efce0801071049u546005e7t7da4311cc0611ccd@mail.gmail.com> <20080107194543.GA2788@flint.arm.linux.org.uk> <20080108023746.GC21068@bingen.suse.de> <20080108024907.GB5264@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080108024907.GB5264@wotan.suse.de> Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Andi Kleen , Jared Hulbert , Martin Schwidefsky , carsteno@linux.vnet.ibm.com, Heiko Carstens , Linux Memory Management List , linux-arch@vger.kernel.org List-ID: On Tue, Jan 08, 2008 at 03:49:07AM +0100, Nick Piggin wrote: > On Tue, Jan 08, 2008 at 03:37:46AM +0100, Andi Kleen wrote: > > > - strongly ordered > > > - bufferable only * > > > - device, sharable * > > > - device, unsharable > > > - memory, bufferable and cacheable, write through, no write allocate > > > - memory, bufferable and cacheable, write back, no write allocate > > > - memory, bufferable and cacheable, write back, write allocate > > > - implementation defined combinations (eg, selecting "minicache") > > > - and a set of 16 states to allow the policy of inner and outer levels > > > of cache to be defined (two bits per level). > > > > Do you need all of those in user space? Perhaps you could give > > the bits different meanings depending on user or kernel space. > > I think Nick et.al. just need the bits for user space; they won't > > care about kernel mappings. > > Yes correct -- they are only for userspace mappings. Though that includes mmaps > of /dev/mem and device drivers etc. /dev/mem can be always special cased by checking the VMA flags, can't it? -Andi -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org