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=-9.8 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 50ED4C0650F for ; Fri, 9 Aug 2019 00:19:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 33E682173C for ; Fri, 9 Aug 2019 00:19:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404970AbfHIATy (ORCPT ); Thu, 8 Aug 2019 20:19:54 -0400 Received: from mga12.intel.com ([192.55.52.136]:58703 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404850AbfHIATx (ORCPT ); Thu, 8 Aug 2019 20:19:53 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Aug 2019 17:19:53 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,363,1559545200"; d="scan'208";a="169158764" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga008.jf.intel.com with ESMTP; 08 Aug 2019 17:19:51 -0700 From: Wei Yang To: akpm@linux-foundation.org, mhocko@suse.com, vbabka@suse.cz, kirill.shutemov@linux.intel.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Wei Yang Subject: [PATCH v2] mm/mmap.c: refine find_vma_prev with rb_last Date: Fri, 9 Aug 2019 08:19:28 +0800 Message-Id: <20190809001928.4950-1-richardw.yang@linux.intel.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When addr is out of the range of the whole rb_tree, pprev will points to the right-most node. rb_tree facility already provides a helper function, rb_last, to do this task. We can leverage this instead of re-implement it. This patch refines find_vma_prev with rb_last to make it a little nicer to read. Signed-off-by: Wei Yang --- v2: leverage rb_last --- mm/mmap.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 7e8c3e8ae75f..f7ed0afb994c 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2270,12 +2270,9 @@ find_vma_prev(struct mm_struct *mm, unsigned long addr, if (vma) { *pprev = vma->vm_prev; } else { - struct rb_node *rb_node = mm->mm_rb.rb_node; - *pprev = NULL; - while (rb_node) { - *pprev = rb_entry(rb_node, struct vm_area_struct, vm_rb); - rb_node = rb_node->rb_right; - } + struct rb_node *rb_node = rb_last(&mm->mm_rb); + *pprev = !rb_node ? NULL : + rb_entry(rb_node, struct vm_area_struct, vm_rb); } return vma; } -- 2.17.1