Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754017Ab2H2PeA (ORCPT ); Wed, 29 Aug 2012 11:34:00 -0400 Received: from e06smtp13.uk.ibm.com ([195.75.94.109]:46979 "EHLO e06smtp13.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753858Ab2H2Pdv (ORCPT ); Wed, 29 Aug 2012 11:33:51 -0400 From: Gerald Schaefer To: Andrew Morton , Andrea Arcangeli , Andi Kleen , Hugh Dickins , Hillf Danton Cc: linux-kernel@vger.kernel.org, Martin Schwidefsky , Heiko Carstens , Gerald Schaefer Subject: [RFC v2 PATCH 3/7] thp: make MADV_HUGEPAGE check for mm->def_flags Date: Wed, 29 Aug 2012 17:33:00 +0200 Message-Id: <1346254384-30046-4-git-send-email-gerald.schaefer@de.ibm.com> X-Mailer: git-send-email 1.7.11.5 In-Reply-To: <1346254384-30046-1-git-send-email-gerald.schaefer@de.ibm.com> References: <1346254384-30046-1-git-send-email-gerald.schaefer@de.ibm.com> x-cbid: 12082915-2966-0000-0000-0000052217B7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1315 Lines: 41 This adds a check to hugepage_madvise(), to refuse MADV_HUGEPAGE if VM_NOHUGEPAGE is set in mm->def_flags. On s390, the VM_NOHUGEPAGE flag will be set in mm->def_flags for kvm processes, to prevent any future thp mappings. In order to also prevent MADV_HUGEPAGE on such an mm, hugepage_madvise() should check mm->def_flags. Signed-off-by: Gerald Schaefer --- mm/huge_memory.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 8bac516..f39cb03 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1464,6 +1464,8 @@ out: int hugepage_madvise(struct vm_area_struct *vma, unsigned long *vm_flags, int advice) { + struct mm_struct *mm = vma->vm_mm; + switch (advice) { case MADV_HUGEPAGE: /* @@ -1471,6 +1473,8 @@ int hugepage_madvise(struct vm_area_struct *vma, */ if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP)) return -EINVAL; + if (mm->def_flags & VM_NOHUGEPAGE) + return -EINVAL; *vm_flags &= ~VM_NOHUGEPAGE; *vm_flags |= VM_HUGEPAGE; /* -- 1.7.11.5 -- 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/