From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ecfrec.frec.bull.fr (ecfrec.frec.bull.fr [129.183.4.8]) by ozlabs.org (Postfix) with ESMTP id E3564DDE21 for ; Thu, 25 Sep 2008 17:42:40 +1000 (EST) Date: Thu, 25 Sep 2008 09:42:31 +0200 From: Sebastien Dugue To: benh@kernel.crashing.org Subject: Re: [PATCH HACK] powerpc: quick hack to get a functional eHEA with hardirq preemption Message-ID: <20080925094231.442a4c75@bull.net> In-Reply-To: <1222327361.8277.179.camel@pasglop> References: <200809231743.23828.ossthema@de.ibm.com> <20080915100406.342e027a@bull.net> <200809240958.m8O9wM7k010996@sullivan.realtime.net> <1222251467.8277.73.camel@pasglop> <20080924143552.29a14f10@bull.net> <1222290917.8277.83.camel@pasglop> <20080925091827.29b5087c@bull.net> <1222327361.8277.179.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: linux-kernel@vger.kernel.org, Milton Miller , linuxppc-dev@ozlabs.org, Christoph Raisch , Paul Mackerras , Jan-Bernd Themann List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 25 Sep 2008 17:22:41 +1000 Benjamin Herrenschmidt wrote: > On Thu, 2008-09-25 at 09:18 +0200, Sebastien Dugue wrote: > > > > > Ok, that's the right approach then. It should work. I don't know > > what > > > the specific problems with HEA are at this stage. > > > > Yep, except as it behaves in way that the current -rt fasteoi flow > > cannot handle. > > We probably need to make a special xics flow handler for -rt that does > what Milton suggested, ie, bring down the CPU priority right away Do you mean creating a custom fasteoi handler into xics.c? Also, it's not clear to me from looking at the code how you go about changing the cpu priority. > and > only EOI later or something like that, instead of masking/unmasking. > > I don't know what are the other potential issues with the HEA though. Don't know either, but that I can test. Thanks, Sebastien. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753364AbYIYHmt (ORCPT ); Thu, 25 Sep 2008 03:42:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752189AbYIYHml (ORCPT ); Thu, 25 Sep 2008 03:42:41 -0400 Received: from ecfrec.frec.bull.fr ([129.183.4.8]:57992 "EHLO ecfrec.frec.bull.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750736AbYIYHmk (ORCPT ); Thu, 25 Sep 2008 03:42:40 -0400 Date: Thu, 25 Sep 2008 09:42:31 +0200 From: Sebastien Dugue To: benh@kernel.crashing.org Cc: Milton Miller , Jan-Bernd Themann , Christoph Raisch , Paul Mackerras , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH HACK] powerpc: quick hack to get a functional eHEA with hardirq preemption Message-ID: <20080925094231.442a4c75@bull.net> In-Reply-To: <1222327361.8277.179.camel@pasglop> References: <200809231743.23828.ossthema@de.ibm.com> <20080915100406.342e027a@bull.net> <200809240958.m8O9wM7k010996@sullivan.realtime.net> <1222251467.8277.73.camel@pasglop> <20080924143552.29a14f10@bull.net> <1222290917.8277.83.camel@pasglop> <20080925091827.29b5087c@bull.net> <1222327361.8277.179.camel@pasglop> X-Mailer: Claws Mail 3.2.0 (GTK+ 2.12.2; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 25 Sep 2008 17:22:41 +1000 Benjamin Herrenschmidt wrote: > On Thu, 2008-09-25 at 09:18 +0200, Sebastien Dugue wrote: > > > > > Ok, that's the right approach then. It should work. I don't know > > what > > > the specific problems with HEA are at this stage. > > > > Yep, except as it behaves in way that the current -rt fasteoi flow > > cannot handle. > > We probably need to make a special xics flow handler for -rt that does > what Milton suggested, ie, bring down the CPU priority right away Do you mean creating a custom fasteoi handler into xics.c? Also, it's not clear to me from looking at the code how you go about changing the cpu priority. > and > only EOI later or something like that, instead of masking/unmasking. > > I don't know what are the other potential issues with the HEA though. Don't know either, but that I can test. Thanks, Sebastien.