From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9593FC3A59E for ; Wed, 21 Aug 2019 08:09:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 688072332A for ; Wed, 21 Aug 2019 08:09:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727122AbfHUIJa (ORCPT ); Wed, 21 Aug 2019 04:09:30 -0400 Received: from mga17.intel.com ([192.55.52.151]:13135 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726224AbfHUIJa (ORCPT ); Wed, 21 Aug 2019 04:09:30 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Aug 2019 01:09:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,412,1559545200"; d="scan'208";a="378061526" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by fmsmga005.fm.intel.com with ESMTP; 21 Aug 2019 01:09:28 -0700 Date: Wed, 21 Aug 2019 16:09:04 +0800 From: Wei Yang To: Matthew Wilcox Cc: Wei Yang , Vlastimil Babka , Christoph Hellwig , akpm@linux-foundation.org, mgorman@techsingularity.net, osalvador@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] mm/mmap.c: extract __vma_unlink_list as counter part for __vma_link_list Message-ID: <20190821080904.GA29221@richard> Reply-To: Wei Yang References: <20190814021755.1977-1-richardw.yang@linux.intel.com> <20190814021755.1977-3-richardw.yang@linux.intel.com> <20190814051611.GA1958@infradead.org> <20190814065703.GA6433@richard> <2c5cdffd-f405-23b8-98f5-37b95ca9b027@suse.cz> <20190820172629.GB4949@bombadil.infradead.org> <20190821005234.GA5540@richard> <20190821005417.GC18776@bombadil.infradead.org> <20190821012244.GA13653@richard> <20190821015939.GA28819@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190821015939.GA28819@bombadil.infradead.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 20, 2019 at 06:59:39PM -0700, Matthew Wilcox wrote: >On Wed, Aug 21, 2019 at 09:22:44AM +0800, Wei Yang wrote: >> On Tue, Aug 20, 2019 at 05:54:17PM -0700, Matthew Wilcox wrote: >> >On Wed, Aug 21, 2019 at 08:52:34AM +0800, Wei Yang wrote: >> >> On Tue, Aug 20, 2019 at 10:26:29AM -0700, Matthew Wilcox wrote: >> >> >On Wed, Aug 14, 2019 at 11:19:37AM +0200, Vlastimil Babka wrote: >> >> >> On 8/14/19 8:57 AM, Wei Yang wrote: >> >> >> > On Tue, Aug 13, 2019 at 10:16:11PM -0700, Christoph Hellwig wrote: >> >> >> >>Btw, is there any good reason we don't use a list_head for vma linkage? >> >> >> > >> >> >> > Not sure, maybe there is some historical reason? >> >> >> >> >> >> Seems it was single-linked until 2010 commit 297c5eee3724 ("mm: make the vma >> >> >> list be doubly linked") and I guess it was just simpler to add the vm_prev link. >> >> >> >> >> >> Conversion to list_head might be an interesting project for some "advanced >> >> >> beginner" in the kernel :) >> >> > >> >> >I'm working to get rid of vm_prev and vm_next, so it would probably be >> >> >wasted effort. >> >> >> >> You mean replace it with list_head? >> > >> >No, replace the rbtree with a new tree. https://lwn.net/Articles/787629/ >> >> Sounds interesting. >> >> While I am not sure the plan is settled down, and how long it would take to >> replace the rb_tree with maple tree. I guess it would probably take some time >> to get merged upstream. >> >> IMHO, it would be good to have this cleanup in current kernel. Do you agree? > >The three cleanups you've posted are fine. Doing more work (ie the >list_head) seems like wasted effort to me. Ah, got your point. I misunderstand it. -- Wei Yang Help you, Help me