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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 8B167C432C0 for ; Mon, 18 Nov 2019 12:24:21 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2CA65206F4 for ; Mon, 18 Nov 2019 12:24:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2CA65206F4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BD2206B000C; Mon, 18 Nov 2019 07:24:20 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BA9626B0010; Mon, 18 Nov 2019 07:24:20 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AE64B6B0266; Mon, 18 Nov 2019 07:24:20 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0116.hostedemail.com [216.40.44.116]) by kanga.kvack.org (Postfix) with ESMTP id 99E5F6B000C for ; Mon, 18 Nov 2019 07:24:20 -0500 (EST) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 49E63180AD80F for ; Mon, 18 Nov 2019 12:24:20 +0000 (UTC) X-FDA: 76169315880.05.oven25_7d140c87fe355 X-HE-Tag: oven25_7d140c87fe355 X-Filterd-Recvd-Size: 3549 Received: from huawei.com (szxga07-in.huawei.com [45.249.212.35]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Mon, 18 Nov 2019 12:24:19 +0000 (UTC) Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 485C4D65A578D96687A4; Mon, 18 Nov 2019 20:24:07 +0800 (CST) Received: from huawei.com (10.175.105.18) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.439.0; Mon, 18 Nov 2019 20:23:57 +0800 From: linmiaohe To: , , , , , , , , , , , , CC: , , Subject: [PATCH v4] mm: get rid of odd jump labels in find_mergeable_anon_vma() Date: Mon, 18 Nov 2019 20:24:04 +0800 Message-ID: <1574079844-17493-1-git-send-email-linmiaohe@huawei.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.105.18] X-CFilter-Loop: Reflected 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: Miaohe Lin The jump labels try_prev and none are not really needed in find_mergeable_anon_vma(), eliminate them to improve readability. Reviewed-by: David Hildenbrand Reviewed-by: John Hubbard Signed-off-by: Miaohe Lin --- -v2: Fix commit descriptions and further simplify the code as suggested by David Hildenbrand and John Hubbard. -v3: Rewrite patch version info. Don't show this in commit log. -v4: Get rid of var near completely as well. --- mm/mmap.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 91d5e097a4ed..4d93bda30eac 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1273,26 +1273,22 @@ static struct anon_vma *reusable_anon_vma(struct vm_area_struct *old, struct vm_ */ struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *vma) { - struct anon_vma *anon_vma; - struct vm_area_struct *near; - - near = vma->vm_next; - if (!near) - goto try_prev; - - anon_vma = reusable_anon_vma(near, vma, near); - if (anon_vma) - return anon_vma; -try_prev: - near = vma->vm_prev; - if (!near) - goto none; - - anon_vma = reusable_anon_vma(near, near, vma); - if (anon_vma) - return anon_vma; -none: + struct anon_vma *anon_vma = NULL; + + /* Try next first. */ + if (vma->vm_next) { + anon_vma = reusable_anon_vma(vma->vm_next, vma, vma->vm_next); + if (anon_vma) + return anon_vma; + } + + /* Try prev next. */ + if (vma->vm_prev) + anon_vma = reusable_anon_vma(vma->vm_prev, vma->vm_prev, vma); + /* + * We might reach here with anon_vma == NULL if we can't find + * any reusable anon_vma. * There's no absolute need to look only at touching neighbours: * we could search further afield for "compatible" anon_vmas. * But it would probably just be a waste of time searching, @@ -1300,7 +1296,7 @@ struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *vma) * We're trying to allow mprotect remerging later on, * not trying to minimize memory used for anon_vmas. */ - return NULL; + return anon_vma; } /* -- 2.21.GIT