From patchwork Tue Oct 13 23:54:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 11836417 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 2DD0B61C for ; Tue, 13 Oct 2020 23:54:08 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DDB7521D7B for ; Tue, 13 Oct 2020 23:54:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="08vl6rbF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DDB7521D7B 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 E8D3F6B00F7; Tue, 13 Oct 2020 19:54:06 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id E3E736B00F8; Tue, 13 Oct 2020 19:54:06 -0400 (EDT) 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 D06F36B00F9; Tue, 13 Oct 2020 19:54:06 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0120.hostedemail.com [216.40.44.120]) by kanga.kvack.org (Postfix) with ESMTP id 9D7F76B00F7 for ; Tue, 13 Oct 2020 19:54:06 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 3E0341EF1 for ; Tue, 13 Oct 2020 23:54:06 +0000 (UTC) X-FDA: 77368558092.07.drop86_501024f27207 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin07.hostedemail.com (Postfix) with ESMTP id 21C661803F9A2 for ; Tue, 13 Oct 2020 23:54:06 +0000 (UTC) X-Spam-Summary: 1,0,0,d805d54dcfc80c7d,d41d8cd98f00b204,akpm@linux-foundation.org,,RULES_HIT:41:355:379:800:960:967:973:981:988:989:1260:1345:1359:1381:1431:1437:1534:1541:1711:1730:1747:1777:1792:2393:2525:2559:2563:2682:2685:2859:2902:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3352:3865:3866:3867:3868:3871:3872:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4321:5007:6261:6653:7576:9025:9545:10004:11026:11658:11914:12043:12048:12296:12297:12438:12517:12519:12555:12679:12986:13069:13311:13357:14181:14384:14721:21080:21451:21627:21939:30012:30054:30070,0,RBL:198.145.29.99:@linux-foundation.org:.lbl8.mailshell.net-64.100.201.201 62.2.0.100;04y83t4heyfctbis3tydegcpf71xqypzxg8egkwtmcd4hbz4khq1za56pg4u819.f4a18fzc3zyn55srd4mnzr14mu4ihgxym65zdj1ps5sgm7rh4xznc13onefw8ys.w-lbl8.mailshell.net-223.238.255.100,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:22,LUA_SUMMARY:none X-HE-Tag: drop86_501024f27207 X-Filterd-Recvd-Size: 2461 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf01.hostedemail.com (Postfix) with ESMTP for ; Tue, 13 Oct 2020 23:54:05 +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 AE6A6221FF; Tue, 13 Oct 2020 23:54:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602633245; bh=ZUiRUd+TI4gD8W1PQh0i+fR97qz+OJPr/OObS+O6Mug=; h=Date:From:To:Subject:In-Reply-To:From; b=08vl6rbFpJi7cdLbmDvYGAQLGjsRnbkH8jpOyx82pUxaGgpngI6AURP46WtKlRjtt 3LZWQVc/uGxn9WtxFoMiu4xwRlbecM5lDBcPsPa2QTv8rc241PF17BFfbMf0joehf2 zjD5ONeQoXN2ONGXs4tzm/K5veEKKLkxJeMJki08= Date: Tue, 13 Oct 2020 16:54:04 -0700 From: Andrew Morton To: akpm@linux-foundation.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, richard.weiyang@linux.alibaba.com, torvalds@linux-foundation.org Subject: [patch 104/181] mm/mmap: not necessary to check mapping separately Message-ID: <20201013235404.3mjS9F61G%akpm@linux-foundation.org> In-Reply-To: <20201013164658.3bfd96cc224d8923e66a9f4e@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: not necessary to check mapping separately *root* with type of struct rb_root_cached is an element of *mapping* with type of struct address_space. This implies when we have a valid *root* it must be a part of valid *mapping*. So we can merge these two checks together to make the code more easy to read and to save some cpu cycles. Link: https://lkml.kernel.org/r/20200913133631.37781-1-richard.weiyang@linux.alibaba.com Signed-off-by: Wei Yang Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton --- mm/mmap.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/mm/mmap.c~mm-mmap-not-necessary-to-check-mapping-separately +++ a/mm/mmap.c @@ -895,10 +895,9 @@ again: anon_vma_interval_tree_post_update_vma(next); anon_vma_unlock_write(anon_vma); } - if (mapping) - i_mmap_unlock_write(mapping); if (root) { + i_mmap_unlock_write(mapping); uprobe_mmap(vma); if (adjust_next)