From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757543AbcBXE2f (ORCPT ); Tue, 23 Feb 2016 23:28:35 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:53979 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932832AbcBXEYX (ORCPT ); Tue, 23 Feb 2016 23:24:23 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Holzheu , Gerald Schaefer , Andrew Morton , Linus Torvalds Subject: [PATCH 4.4 111/137] numa: fix /proc//numa_maps for hugetlbfs on s390 Date: Tue, 23 Feb 2016 19:34:02 -0800 Message-Id: <20160224033420.868149660@linuxfoundation.org> X-Mailer: git-send-email 2.7.1 In-Reply-To: <20160224033417.270530882@linuxfoundation.org> References: <20160224033417.270530882@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Holzheu commit 5c2ff95e41c9290d16556cd02e35b25d81be8fe0 upstream. 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. Signed-off-by: Michael Holzheu Reviewed-by: Gerald Schaefer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/proc/task_mmu.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1473,18 +1473,19 @@ static int gather_pte_stats(pmd_t *pmd, static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask, unsigned long addr, unsigned long end, struct mm_walk *walk) { + pte_t huge_pte = huge_ptep_get(pte); struct numa_maps *md; struct page *page; - if (!pte_present(*pte)) + if (!pte_present(huge_pte)) return 0; - page = pte_page(*pte); + page = pte_page(huge_pte); if (!page) return 0; md = walk->private; - gather_stats(page, md, pte_dirty(*pte), 1); + gather_stats(page, md, pte_dirty(huge_pte), 1); return 0; }