From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755874Ab1KABJx (ORCPT ); Mon, 31 Oct 2011 21:09:53 -0400 Received: from mga03.intel.com ([143.182.124.21]:46282 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753728Ab1KABJx (ORCPT ); Mon, 31 Oct 2011 21:09:53 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.69,435,1315206000"; d="scan'208";a="31980912" Subject: Re: [PATCH][mm/memory.c]: transparent hugepage check condition missed From: Shaohua Li To: Guanjun He Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" In-Reply-To: <1320049412-12642-1-git-send-email-gjhe@suse.com> References: <1320049412-12642-1-git-send-email-gjhe@suse.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 01 Nov 2011 09:18:08 +0800 Message-ID: <1320110288.22361.190.camel@sli10-conroe> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-10-31 at 16:23 +0800, Guanjun He wrote: > For the transparent hugepage module still does not support > tmpfs and cache,the check condition should always be checked > to make sure that it only affect the anonymous maps, the > original check condition missed this, this patch is to fix this. > Otherwise,the hugepage may affect the file-backed maps, > then the cache for the small-size pages will be unuseful, > and till now there is still no implementation for hugepage's cache. > > Signed-off-by: Guanjun He > --- > mm/memory.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index a56e3ba..79b85fe 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3475,7 +3475,8 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, > if (pmd_trans_huge(orig_pmd)) { > if (flags & FAULT_FLAG_WRITE && > !pmd_write(orig_pmd) && > - !pmd_trans_splitting(orig_pmd)) > + !pmd_trans_splitting(orig_pmd) && > + !vma->vm_ops) > return do_huge_pmd_wp_page(mm, vma, address, > pmd, orig_pmd); > return 0; so if vma->vm_ops != NULL, how could the pmd_trans_huge(orig_pmd) be true? We never enable THP if vma->vm_ops != NULL.