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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY autolearn=ham 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 E11E6C4646D for ; Fri, 10 Aug 2018 18:24:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A9C422242C for ; Fri, 10 Aug 2018 18:24:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A9C422242C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728381AbeHJUzP (ORCPT ); Fri, 10 Aug 2018 16:55:15 -0400 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:33745 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727570AbeHJUzP (ORCPT ); Fri, 10 Aug 2018 16:55:15 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R671e4;CH=green;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01f04446;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=14;SR=0;TI=SMTPD_---0T6QQEkV_1533925426; Received: from US-143344MP.local(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0T6QQEkV_1533925426) by smtp.aliyun-inc.com(127.0.0.1); Sat, 11 Aug 2018 02:23:54 +0800 Subject: Re: [RFC v7 PATCH 1/4] mm: refactor do_munmap() to extract the common part To: Matthew Wilcox Cc: mhocko@kernel.org, ldufour@linux.vnet.ibm.com, kirill@shutemov.name, vbabka@suse.cz, akpm@linux-foundation.org, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@redhat.com, namhyung@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <1533857763-43527-1-git-send-email-yang.shi@linux.alibaba.com> <1533857763-43527-2-git-send-email-yang.shi@linux.alibaba.com> <20180810174150.GA6487@bombadil.infradead.org> From: Yang Shi Message-ID: <30ee3dd0-a794-1c93-dd22-5c643a9037a6@linux.alibaba.com> Date: Fri, 10 Aug 2018 11:23:45 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180810174150.GA6487@bombadil.infradead.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/10/18 10:41 AM, Matthew Wilcox wrote: > On Fri, Aug 10, 2018 at 07:36:00AM +0800, Yang Shi wrote: >> +static inline bool addr_ok(unsigned long start, size_t len) > Maybe munmap_range_ok()? Otherwise some of the conditions here don't make > sense for such a generic sounding function. I don't know. I think the argument is about munmap_ prefix should be used. > >> { >> - unsigned long end; >> - struct vm_area_struct *vma, *prev, *last; >> - >> if ((offset_in_page(start)) || start > TASK_SIZE || len > TASK_SIZE-start) >> - return -EINVAL; >> + return false; >> >> - len = PAGE_ALIGN(len); >> - if (len == 0) >> - return -EINVAL; >> + if (PAGE_ALIGN(len) == 0) >> + return false; >> + >> + return true; >> +} >> + >> +/* >> + * munmap_lookup_vma: find the first overlap vma and split overlap vmas. >> + * @mm: mm_struct >> + * @start: start address >> + * @end: end address >> + * >> + * returns the pointer to vma, NULL or err ptr when spilt_vma returns error. > kernel-doc prefers: > > * Return: %NULL if no VMA overlaps this range. An ERR_PTR if an > * overlapping VMA could not be split. Otherwise a pointer to the first > * VMA which overlaps the range. Ok, will fix it. > >> + */ >> +static struct vm_area_struct *munmap_lookup_vma(struct mm_struct *mm, >> + unsigned long start, unsigned long end) >> +{ >> + struct vm_area_struct *vma, *prev, *last; >> >> /* Find the first overlapping VMA */ >> vma = find_vma(mm, start); >> if (!vma) >> - return 0; >> - prev = vma->vm_prev; >> - /* we have start < vma->vm_end */ >> + return NULL; >> >> + /* we have start < vma->vm_end */ > Can you remove the duplicate spaces here? Sure Thanks, Yang