From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [patch 0/6] Strong Access Ordering page attributes for POWER7 From: Dave Kleikamp To: benh@kernel.crashing.org, Joel Schopp In-Reply-To: <1215128392.7960.7.camel@pasglop> References: <20080618223254.966080905@linux.vnet.ibm.com> <1215128392.7960.7.camel@pasglop> Content-Type: text/plain Date: Mon, 07 Jul 2008 09:05:40 -0500 Message-Id: <1215439540.16098.15.camel@norville.austin.ibm.com> Mime-Version: 1.0 Cc: linux-mm@kvack.org, Andrew Morton , Paul Mackerras , Linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2008-07-04 at 09:39 +1000, Benjamin Herrenschmidt wrote: > On Wed, 2008-06-18 at 17:32 -0500, shaggy@linux.vnet.ibm.com wrote: > > Andrew, > > > > The first patch in this series hits architecture independent code, but the > > rest is contained in the powerpc subtree. Could you pick up the first > > patch into -mm? I can send the rest of them through the powerpc git tree. > > The first patch and the rest of the set are independent and can be merged > > in either order. > > ../.. > > I was wondering... how do we inform userspace that this is available ? > Same question with adding the endian bit on 4xx which I plan to do using > your infrastructure... I hadn't really given it much thought. Is there a simple way to determine if the cpu is power 7 or newer? It's not elegant, but a program could call mmap() with PROT_SAO set and check for errno == EINVAL. Then call again without PROT_SAO, if it needs to. > We haven't defined a user-visible feature bit (and besides, we're really > getting short on these...). This is becoming a bit of concern btw (the > running out of bits). Maybe we should start defining an AT_HWCAP2 for > powerpc and get libc updated to pick it up ? Joel, Any thoughts? Shaggy -- David Kleikamp IBM Linux Technology Center