From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 85F76DDDD8 for ; Thu, 2 Aug 2007 19:14:49 +1000 (EST) Subject: Re: [PATCH] fixes for the SLB shadow buffer From: Benjamin Herrenschmidt To: Michael Neuling In-Reply-To: <17854.1186045405@neuling.org> References: <17055.1185944172@neuling.org> <18096.6654.934841.561238@cargo.ozlabs.ibm.com> <31580.1185948147@neuling.org> <1186004885.22717.50.camel@farscape.rchland.ibm.com> <24613.1186034191@neuling.org> <1186039870.5495.595.camel@localhost.localdomain> <13166.1186045008@neuling.org> <1186045096.5495.617.camel@localhost.localdomain> <17854.1186045405@neuling.org> Content-Type: text/plain Date: Thu, 02 Aug 2007 19:14:39 +1000 Message-Id: <1186046080.5495.620.camel@localhost.localdomain> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, will_schmidt@vnet.ibm.com, Paul Mackerras List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2007-08-02 at 19:03 +1000, Michael Neuling wrote: > > > > Ok, that was missing from your description :-) > > Sorry... so ditch the barriers? As you like. The reason why you can ditch them is purely because you know for sure that the only case the firmware will access those shadows from another CPU is that one and it happens to be just right. What are the chances that in the future, FW will do something different and nobody will "fix" the code ? Considering that eieios are fairly cheap and it's not a very hot code path as far as I can tell, I'd rather keep them. Cheers, Ben.