From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757013AbcAZK5L (ORCPT ); Tue, 26 Jan 2016 05:57:11 -0500 Received: from e06smtp15.uk.ibm.com ([195.75.94.111]:47339 "EHLO e06smtp15.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756943AbcAZK5E (ORCPT ); Tue, 26 Jan 2016 05:57:04 -0500 X-IBM-Helo: d06dlp03.portsmouth.uk.ibm.com X-IBM-MailFrom: holzheu@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org;linux-mm@vger.kernel.org Date: Tue, 26 Jan 2016 11:56:58 +0100 From: Michael Holzheu To: Andrew Morton Cc: Martin Schwidefsky , Heiko Carstens , Gerald Schaefer , linux-mm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] numa: fix /proc//numa_maps for hugetlbfs on s390 Message-ID: <20160126115658.21b9c235@holzheu> In-Reply-To: <20160125145116.30603e678b1f787d51ab3f5e@linux-foundation.org> References: <1453739442-57738-1-git-send-email-holzheu@linux.vnet.ibm.com> <20160125145116.30603e678b1f787d51ab3f5e@linux-foundation.org> Organization: IBM X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16012610-0021-0000-0000-00001FF08DED Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 25 Jan 2016 14:51:16 -0800 Andrew Morton wrote: > On Mon, 25 Jan 2016 17:30:42 +0100 Michael Holzheu wrote: > > > When working with hugetlbfs ptes (which are actually pmds) is not > > valid to directly use pte functions like pte_present() because the > > hardware bit layout of pmds and ptes can be different. This is the > > case on s390. Therefore we have to convert the hugetlbfs ptes first > > into a valid pte encoding with huge_ptep_get(). > > > > Currently the /proc//numa_maps code uses hugetlbfs ptes without > > huge_ptep_get(). On s390 this leads to the following two problems: > > > > 1) The pte_present() function returns false (instead of true) for > > PROT_NONE hugetlb ptes. Therefore PROT_NONE vmas are missing > > completely in the "numa_maps" output. > > > > 2) The pte_dirty() function always returns false for all hugetlb ptes. > > Therefore these pages are reported as "mapped=xxx" instead of > > "dirty=xxx". > > > > Therefore use huge_ptep_get() to correctly convert the hugetlb ptes. > > I'm aiming this at 4.5 only. Please let me know if you think that a > -stable backport is warranted. S390 has NUMA support since kernel 4.3, therefore: Cc: stable@vger.kernel.org # v4.3+ Michael