From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753289AbbC3OKu (ORCPT ); Mon, 30 Mar 2015 10:10:50 -0400 Received: from e28smtp07.in.ibm.com ([122.248.162.7]:44011 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752998AbbC3OKr (ORCPT ); Mon, 30 Mar 2015 10:10:47 -0400 From: "Aneesh Kumar K.V" To: "Kirill A. Shutemov" , Andrew Morton , Andrea Arcangeli Cc: Dave Hansen , Hugh Dickins , Mel Gorman , Rik van Riel , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Steve Capper , Johannes Weiner , Michal Hocko , Jerome Marchand , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Kirill A. Shutemov" Subject: Re: [PATCHv4 18/24] thp, mm: split_huge_page(): caller need to lock page In-Reply-To: <1425486792-93161-19-git-send-email-kirill.shutemov@linux.intel.com> References: <1425486792-93161-1-git-send-email-kirill.shutemov@linux.intel.com> <1425486792-93161-19-git-send-email-kirill.shutemov@linux.intel.com> User-Agent: Notmuch/0.19+30~gd241a48 (http://notmuchmail.org) Emacs/24.4.1 (x86_64-pc-linux-gnu) Date: Mon, 30 Mar 2015 19:40:29 +0530 Message-ID: <87mw2ulgoa.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15033014-0025-0000-0000-000004066AD8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "Kirill A. Shutemov" writes: > We're going to use migration entries instead of compound_lock() to > stabilize page refcounts. Setup and remove migration entries require > page to be locked. > > Some of split_huge_page() callers already have the page locked. Let's > require everybody to lock the page before calling split_huge_page(). > > Signed-off-by: Kirill A. Shutemov Why not have split_huge_page_locked/unlocked, and call the one which takes lock internally every where ? -aneesh From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f177.google.com (mail-pd0-f177.google.com [209.85.192.177]) by kanga.kvack.org (Postfix) with ESMTP id DA8D06B0032 for ; Mon, 30 Mar 2015 10:10:41 -0400 (EDT) Received: by pddn5 with SMTP id n5so60822400pdd.2 for ; Mon, 30 Mar 2015 07:10:41 -0700 (PDT) Received: from e28smtp02.in.ibm.com (e28smtp02.in.ibm.com. [122.248.162.2]) by mx.google.com with ESMTPS id jp11si12099145pbb.255.2015.03.30.07.10.39 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 30 Mar 2015 07:10:40 -0700 (PDT) Received: from /spool/local by e28smtp02.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 30 Mar 2015 19:40:36 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 9E70AE0056 for ; Mon, 30 Mar 2015 19:42:52 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay05.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t2UEAVMn33685538 for ; Mon, 30 Mar 2015 19:40:33 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t2UDxQP5019317 for ; Mon, 30 Mar 2015 19:29:27 +0530 From: "Aneesh Kumar K.V" Subject: Re: [PATCHv4 18/24] thp, mm: split_huge_page(): caller need to lock page In-Reply-To: <1425486792-93161-19-git-send-email-kirill.shutemov@linux.intel.com> References: <1425486792-93161-1-git-send-email-kirill.shutemov@linux.intel.com> <1425486792-93161-19-git-send-email-kirill.shutemov@linux.intel.com> Date: Mon, 30 Mar 2015 19:40:29 +0530 Message-ID: <87mw2ulgoa.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" , Andrew Morton , Andrea Arcangeli Cc: Dave Hansen , Hugh Dickins , Mel Gorman , Rik van Riel , Vlastimil Babka , Christoph Lameter , Naoya Horiguchi , Steve Capper , Johannes Weiner , Michal Hocko , Jerome Marchand , linux-kernel@vger.kernel.org, linux-mm@kvack.org "Kirill A. Shutemov" writes: > We're going to use migration entries instead of compound_lock() to > stabilize page refcounts. Setup and remove migration entries require > page to be locked. > > Some of split_huge_page() callers already have the page locked. Let's > require everybody to lock the page before calling split_huge_page(). > > Signed-off-by: Kirill A. Shutemov Why not have split_huge_page_locked/unlocked, and call the one which takes lock internally every where ? -aneesh -- 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