From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Date: Fri, 17 Mar 2006 14:09:04 +0000 Subject: Re: [patch 2/2] mspec driver Message-Id: <441AC300.8020003@yahoo.com.au> List-Id: References: <20060316163728.06f49c00.akpm@osdl.org> <441ABB68.1020502@yahoo.com.au> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jes Sorensen Cc: Andrew Morton , torvalds@osdl.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, hch@lst.de, cotte@de.ibm.com, Hugh Dickins Jes Sorensen wrote: >>>>>>"Nick" = Nick Piggin writes: > > > Nick> Jes Sorensen wrote: > >>>+ vma->vm_flags |= (VM_IO | VM_LOCKED | VM_RESERVED | VM_PFNMAP); > > > Nick> VM_PFNMAP actually has a fairly specific meaning [unlike the > Nick> rest of them :)] so you should be careful with it. Actually if > Nick> you set vm_pgoff in the right way, then that should enable you > Nick> to do COWs on these areas if that is what you want. > > Yup, I went through that when I started using it. I think you guided > me through it :-) > > We don't want COW here as the access is backed by special behavior in > the memory controller. We only allow shared mappings for that reason. > No problem, I think you should just stop using the VM_PFNMAP flag then. [Linus should jump in here if I'm wrong ;)] -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com