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: Benjamin Herrenschmidt To: Joel Schopp In-Reply-To: <48728942.6050007@austin.ibm.com> References: <20080618223254.966080905@linux.vnet.ibm.com> <1215128392.7960.7.camel@pasglop> <1215439540.16098.15.camel@norville.austin.ibm.com> <48728942.6050007@austin.ibm.com> Content-Type: text/plain Date: Tue, 08 Jul 2008 08:27:57 +1000 Message-Id: <1215469677.8970.148.camel@pasglop> Mime-Version: 1.0 Cc: linux-mm@kvack.org, Andrew Morton , Dave Kleikamp , Paul Mackerras , Linuxppc-dev@ozlabs.org Reply-To: benh@kernel.crashing.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2008-07-07 at 16:23 -0500, Joel Schopp wrote: > >> 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? > Is it a required or optional feature of the 2.06 architecture spec? If it's required you could just use that. It doesn't solve the problem more generically if other archs decide to implement it though. And then we start having to expose 2.06S vs. 2.06E .. nah. I think for now, for SAO, the idea that one can "try" and if -EINVAL, try again without might work fine. Cheers, Ben.