From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751785AbbINSUi (ORCPT ); Mon, 14 Sep 2015 14:20:38 -0400 Received: from mail-wi0-f182.google.com ([209.85.212.182]:38571 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750944AbbINSUg (ORCPT ); Mon, 14 Sep 2015 14:20:36 -0400 Date: Mon, 14 Sep 2015 21:20:33 +0300 From: "Kirill A. Shutemov" To: Oleg Nesterov Cc: "Kirill A. Shutemov" , Will Deacon , hpa@zytor.com, luto@amacapital.net, dave.hansen@linux.intel.com, mingo@elte.hu, minchan@kernel.org, tglx@linutronix.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: LTP regressions due to 6dc296e7df4c ("mm: make sure all file VMAs have ->vm_ops set") Message-ID: <20150914182033.GA4165@node.dhcp.inet.fi> References: <20150914105346.GB23878@arm.com> <20150914115800.06242CE@black.fi.intel.com> <20150914170547.GA28535@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150914170547.GA28535@redhat.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 14, 2015 at 07:05:47PM +0200, Oleg Nesterov wrote: > On 09/14, Kirill A. Shutemov wrote: > > > > Fix is below. I don't really like it, but I cannot find any better > > solution. > > Me too... > > But this change "documents" the nasty special "vm_file && !vm_ops" case, and > I am not sure how we can remove it later... > > So perhaps we should change vma_is_anonymous() back to check ->fault too, > > static inline bool vma_is_anonymous(struct vm_area_struct *vma) > { > - return !vma->vm_ops; > + return !vma->vm_ops || !vma->vm_ops->fault; No. This would give a lot false positives from drives which setup page tables upfront and don't use ->fault at all. > } > > and remove the "vma->vm_file && !vma->vm_ops" checks in mmap_region() paths. > > I dunno. > > Oleg. > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org -- Kirill A. Shutemov