Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751551AbWIAPbW (ORCPT ); Fri, 1 Sep 2006 11:31:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751552AbWIAPbW (ORCPT ); Fri, 1 Sep 2006 11:31:22 -0400 Received: from mtagate3.de.ibm.com ([195.212.29.152]:60331 "EHLO mtagate3.de.ibm.com") by vger.kernel.org with ESMTP id S1751544AbWIAPbV (ORCPT ); Fri, 1 Sep 2006 11:31:21 -0400 Subject: Re: [patch 3/9] Guest page hinting: volatile page cache. From: Martin Schwidefsky Reply-To: schwidefsky@de.ibm.com To: Dave Hansen Cc: linux-kernel@vger.kernel.org, virtualization@lists.osdl.org, akpm@osdl.org, nickpiggin@yahoo.com.au, frankeh@watson.ibm.com, rhim@cc.gateh.edu, Andy Whitcroft In-Reply-To: <1157122667.28577.69.camel@localhost.localdomain> References: <20060901110948.GD15684@skybase> <1157122667.28577.69.camel@localhost.localdomain> Content-Type: text/plain Organization: IBM Corporation Date: Fri, 01 Sep 2006 17:31:14 +0200 Message-Id: <1157124674.21733.13.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1255 Lines: 35 On Fri, 2006-09-01 at 07:57 -0700, Dave Hansen wrote: > > +#define PG_state_change 21 /* HV page state is changing. */ > > +#define PG_discarded 22 /* HV page has been discarded. */ > > We're already desperately short on page flags on 32-bit architectures. > It seems a wee bit silly to add two arch-generic flags for what is a > very specialized arch-specific feature at this point. There are even three additional page flags if you apply the full set of patches. > I know that there are 32-bit s390 kernels, but would this be a > reasonable feature to restrict to only 64-bit kernels? That might be a > decent compromise. Yes, it is definitly an option to make this a 64-bit only features. In particular because the ESSA instruction that is used on s390 is only available in zarch mode (=64 bit). -- blue skies, Martin. Martin Schwidefsky Linux for zSeries Development & Services IBM Deutschland Entwicklung GmbH "Reality continues to ruin my life." - Calvin. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/