From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754815AbZBDBJJ (ORCPT ); Tue, 3 Feb 2009 20:09:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751577AbZBDBI4 (ORCPT ); Tue, 3 Feb 2009 20:08:56 -0500 Received: from sj-iport-6.cisco.com ([171.71.176.117]:62013 "EHLO sj-iport-6.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751508AbZBDBI4 (ORCPT ); Tue, 3 Feb 2009 20:08:56 -0500 X-IronPort-AV: E=Sophos;i="4.37,375,1231113600"; d="scan'208";a="242370480" From: Roland Dreier To: Benjamin Herrenschmidt , Eli Cohen Cc: linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org Subject: FW: [PATCH] powerpc/mm: Export HPAGE_SHIFT References: <20090203164930.GA10101@mtls03> X-Message-Flag: Warning: May contain useful information Date: Tue, 03 Feb 2009 17:08:54 -0800 In-Reply-To: <20090203164930.GA10101@mtls03> (Eli Cohen's message of "Tue, 3 Feb 2009 18:49:30 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.60 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-OriginalArrivalTime: 04 Feb 2009 01:08:55.0135 (UTC) FILETIME=[266E46F0:01C98665] Authentication-Results: sj-dkim-4; header.From=rdreier@cisco.com; dkim=pass ( sig from cisco.com/sjdkim4002 verified; ); Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Forwarding Eli's patch below, since PowerPC guys may have missed it. I guess the question for Ben et al is whether there is any issue with exporting HPAGE_SHIFT for modules (can be EXPORT_SYMBOL_GPL if you feel it's an internal detail). It would probably make sense to roll this change into the mlx4 change that Eli alludes to below and merge through my tree (with ppc maintainer acks of course), rather than splitting this patch out and introducing cross-tree dependencies (and also separating the rationale for the change from the change itself). Thanks, Roland Drivers may want to take advantage of the large pages used for memory obtained from hugetlbfs. One example is mlx4_ib which can use much less MTT entries (in the order of HPAGE_SIZE / PAGE_SIZE) when registering such memory, thus scale significantly better when registering larger memory regions. Other drivers could also benefit from this. Signed-off-by: Eli Cohen --- arch/powerpc/mm/hash_utils_64.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index 8d5b475..6cff8c7 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -104,6 +104,7 @@ int mmu_highuser_ssize = MMU_SEGSIZE_256M; u16 mmu_slb_size = 64; #ifdef CONFIG_HUGETLB_PAGE unsigned int HPAGE_SHIFT; +EXPORT_SYMBOL(HPAGE_SHIFT); #endif #ifdef CONFIG_PPC_64K_PAGES int mmu_ci_restrictions; -- 1.6.1