Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755616AbXKFIzU (ORCPT ); Tue, 6 Nov 2007 03:55:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751729AbXKFIzH (ORCPT ); Tue, 6 Nov 2007 03:55:07 -0500 Received: from mtagate6.de.ibm.com ([195.212.29.155]:27846 "EHLO mtagate6.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751327AbXKFIzG (ORCPT ); Tue, 6 Nov 2007 03:55:06 -0500 Subject: problem in follow_hugetlb_page on ppc64 architecture with get_user_pages To: linux-kernel , linux-ppc , general@lists.openfabrics.org Cc: agl@us.ibm.com, Hoang-Nam Nguyen , Roland Dreier X-Mailer: Lotus Notes Release 8.0 August 02, 2007 Message-ID: From: Christoph Raisch Date: Tue, 6 Nov 2007 08:42:40 +0100 X-MIMETrack: Serialize by Router on D12ML067/12/M/IBM(Release 7.0.2HF71 | November 3, 2006) at 06/11/2007 09:55:02 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 797 Lines: 23 Hello, if get_user_pages is used on a hugetlb vma, and there was no previous write to the pages, follow_hugetlb_page will call ret = hugetlb_fault(mm, vma, vaddr, 0), although the page should be used for write access in get_user_pages. We currently see this when testing Infiniband on ppc64 with ehca + hugetlbfs. >From reading the code this should also be an issue on other architectures. Roland, Adam, are you aware of anything in this area with mellanox Infiniband cards or other usages with I/O adapters? Gruss / Regards Christoph R. + Nam Ng. - 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/