From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f200.google.com (mail-wr0-f200.google.com [209.85.128.200]) by kanga.kvack.org (Postfix) with ESMTP id 4F6926B03B1 for ; Wed, 19 Apr 2017 09:46:01 -0400 (EDT) Received: by mail-wr0-f200.google.com with SMTP id u77so2478205wrb.6 for ; Wed, 19 Apr 2017 06:46:01 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id a64si3666389wrc.296.2017.04.19.06.45.59 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 19 Apr 2017 06:46:00 -0700 (PDT) Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v3JDd52R044975 for ; Wed, 19 Apr 2017 09:45:58 -0400 Received: from e06smtp15.uk.ibm.com (e06smtp15.uk.ibm.com [195.75.94.111]) by mx0b-001b2d01.pphosted.com with ESMTP id 29x744x8h9-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 19 Apr 2017 09:45:58 -0400 Received: from localhost by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 19 Apr 2017 14:45:56 +0100 Subject: Re: [RFC 2/4] Deactivate mmap_sem assert References: <582009a3f9459de3d8def1e76db46e815ea6153c.1492595897.git.ldufour@linux.vnet.ibm.com> <20170419123051.GA5730@worktop> From: Laurent Dufour Date: Wed, 19 Apr 2017 15:45:50 +0200 MIME-Version: 1.0 In-Reply-To: <20170419123051.GA5730@worktop> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Message-Id: Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: linux-mm@kvack.org, Davidlohr Bueso , akpm@linux-foundation.org, Jan Kara , "Kirill A . Shutemov" , Michal Hocko , Mel Gorman , haren@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com, Paul.McKenney@us.ibm.com, linux-kernel@vger.kernel.org On 19/04/2017 14:30, Peter Zijlstra wrote: > On Wed, Apr 19, 2017 at 02:18:25PM +0200, Laurent Dufour wrote: >> When mmap_sem will be moved to a range lock, some assertion done in >> the code are no more valid, like the one ensuring mmap_sem is held. >> > > Why are they no longer valid? I didn't explain that very well.. When using a range lock we can't check that the lock is simply held, but if the range we are interesting on is locked or not. As I mentioned this patch will have to be reverted / reviewed once the range lock is providing dedicated APIs, but some check might be difficult to adapt to a range. -- 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