Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933225AbbESP1s (ORCPT ); Tue, 19 May 2015 11:27:48 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:22176 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933196AbbESP1p (ORCPT ); Tue, 19 May 2015 11:27:45 -0400 X-IronPort-AV: E=Sophos;i="5.13,458,1427760000"; d="scan'208";a="266538010" Message-ID: <555B566D.8090805@citrix.com> Date: Tue, 19 May 2015 16:27:41 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.4.0 MIME-Version: 1.0 To: Julien Grall , CC: Russell King , , , , , David Vrabel , "Boris Ostrovsky" , Subject: Re: [Xen-devel] [RFC 17/23] xen/grant-table: Make it running on 64KB granularity References: <1431622863-28575-1-git-send-email-julien.grall@citrix.com> <1431622863-28575-18-git-send-email-julien.grall@citrix.com> In-Reply-To: <1431622863-28575-18-git-send-email-julien.grall@citrix.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 855 Lines: 22 On 14/05/15 18:00, Julien Grall wrote: > The Xen interface is using 4KB page granularity. This means that each > grant is 4KB. > > The current implementation allocates a Linux page per grant. On Linux > using 64KB page granularity, only the first 4KB of the page will be > used. > > We could decrease the memory wasted by sharing the page with multiple > grant. It will require some care with the {Set,Clear}ForeignPage macro. > > Note that no changes has been made in the x86 code because both Linux > and Xen will only use 4KB page granularity. Reviewed-by: David Vrabel David -- 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/