From patchwork Sun Dec 1 01:50:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11268243 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CFC54112B for ; Sun, 1 Dec 2019 01:50:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9C807206F0 for ; Sun, 1 Dec 2019 01:50:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="gYE+/12Y" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9C807206F0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 780E76B0298; Sat, 30 Nov 2019 20:50:55 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 730F26B029A; Sat, 30 Nov 2019 20:50:55 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5F9A06B029B; Sat, 30 Nov 2019 20:50:55 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0176.hostedemail.com [216.40.44.176]) by kanga.kvack.org (Postfix) with ESMTP id 47CA06B0298 for ; Sat, 30 Nov 2019 20:50:55 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 02843180AD817 for ; Sun, 1 Dec 2019 01:50:55 +0000 (UTC) X-FDA: 76214894070.27.verse90_7f64042a4058 X-Spam-Summary: 2,0,0,fa77ac76a5443632,d41d8cd98f00b204,akpm@linux-foundation.org,:akpm@linux-foundation.org::mgorman@techsingularity.net:mm-commits@vger.kernel.org:richardw.yang@linux.intel.com:torvalds@linux-foundation.org:vbabka@suse.cz:willy@infradead.org,RULES_HIT:41:355:379:800:960:967:973:988:989:1260:1263:1345:1381:1431:1437:1534:1542:1711:1730:1747:1777:1792:2198:2199:2393:2525:2559:2563:2682:2685:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3353:3865:3866:3867:3870:3871:3872:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6261:6653:7576:8599:9010:9025:9545:10004:10913:11026:11658:11914:12043:12048:12296:12297:12517:12519:12555:12679:12783:12986:13161:13229:14181:14721:14849:21080:21451:21627:21939:30012:30051:30054,0,RBL:error,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:3,LUA_SUMMARY:none X-HE-Tag: verse90_7f64042a4058 X-Filterd-Recvd-Size: 4144 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf07.hostedemail.com (Postfix) with ESMTP for ; Sun, 1 Dec 2019 01:50:54 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 855292073C; Sun, 1 Dec 2019 01:50:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575165053; bh=dSnhQ39iU0lth5tK/Nzm9cXeYscgXQH+T9+A/REhXhc=; h=Date:From:To:Subject:From; b=gYE+/12YDsTB850cc6J7MSL7TNKOZyow6Dv0EwScbqSSnYM9e+T6Quf8Gs/HbjSQs tfTf06+ljuyD9JN3+Taq0nlWIKI83CRdIjgT5gL6uWrMEUv1BV7RfL5wHhVrMLzNbo VV1O+43yINyibfEMEdOznMeb3DUdbAuf3xhW1tps= Date: Sat, 30 Nov 2019 17:50:53 -0800 From: akpm@linux-foundation.org To: akpm@linux-foundation.org, linux-mm@kvack.org, mgorman@techsingularity.net, mm-commits@vger.kernel.org, richardw.yang@linux.intel.com, torvalds@linux-foundation.org, vbabka@suse.cz, willy@infradead.org Subject: [patch 033/158] mm/mmap.c: rb_parent is not necessary in __vma_link_list() Message-ID: <20191201015053.yBGUELT9h%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Wei Yang Subject: mm/mmap.c: rb_parent is not necessary in __vma_link_list() Now we use rb_parent to get next, while this is not necessary. When prev is NULL, this means vma should be the first element in the list. Then next should be current first one (mm->mmap), no matter whether we have parent or not. After removing it, the code shows the beauty of symmetry. Link: http://lkml.kernel.org/r/20190813032656.16625-1-richardw.yang@linux.intel.com Signed-off-by: Wei Yang Acked-by: Andrew Morton Cc: Mel Gorman Cc: Vlastimil Babka Cc: Matthew Wilcox Signed-off-by: Andrew Morton --- mm/internal.h | 2 +- mm/mmap.c | 2 +- mm/nommu.c | 2 +- mm/util.c | 8 ++------ 4 files changed, 5 insertions(+), 9 deletions(-) --- a/mm/internal.h~mm-mmapc-rb_parent-is-not-necessary-in-__vma_link_list +++ a/mm/internal.h @@ -290,7 +290,7 @@ static inline bool is_data_mapping(vm_fl /* mm/util.c */ void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, - struct vm_area_struct *prev, struct rb_node *rb_parent); + struct vm_area_struct *prev); void __vma_unlink_list(struct mm_struct *mm, struct vm_area_struct *vma); #ifdef CONFIG_MMU --- a/mm/mmap.c~mm-mmapc-rb_parent-is-not-necessary-in-__vma_link_list +++ a/mm/mmap.c @@ -641,7 +641,7 @@ __vma_link(struct mm_struct *mm, struct struct vm_area_struct *prev, struct rb_node **rb_link, struct rb_node *rb_parent) { - __vma_link_list(mm, vma, prev, rb_parent); + __vma_link_list(mm, vma, prev); __vma_link_rb(mm, vma, rb_link, rb_parent); } --- a/mm/nommu.c~mm-mmapc-rb_parent-is-not-necessary-in-__vma_link_list +++ a/mm/nommu.c @@ -648,7 +648,7 @@ static void add_vma_to_mm(struct mm_stru if (rb_prev) prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb); - __vma_link_list(mm, vma, prev, parent); + __vma_link_list(mm, vma, prev); } /* --- a/mm/util.c~mm-mmapc-rb_parent-is-not-necessary-in-__vma_link_list +++ a/mm/util.c @@ -271,7 +271,7 @@ void *memdup_user_nul(const void __user EXPORT_SYMBOL(memdup_user_nul); void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, - struct vm_area_struct *prev, struct rb_node *rb_parent) + struct vm_area_struct *prev) { struct vm_area_struct *next; @@ -280,12 +280,8 @@ void __vma_link_list(struct mm_struct *m next = prev->vm_next; prev->vm_next = vma; } else { + next = mm->mmap; mm->mmap = vma; - if (rb_parent) - next = rb_entry(rb_parent, - struct vm_area_struct, vm_rb); - else - next = NULL; } vma->vm_next = next; if (next)