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, USER_AGENT_GIT 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 C1D66CA9EAF for ; Mon, 28 Oct 2019 02:15:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F6DE20717 for ; Mon, 28 Oct 2019 02:15:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729887AbfJ1CPk (ORCPT ); Sun, 27 Oct 2019 22:15:40 -0400 Received: from mga17.intel.com ([192.55.52.151]:5377 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727598AbfJ1CPj (ORCPT ); Sun, 27 Oct 2019 22:15:39 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Oct 2019 19:15:39 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,238,1569308400"; d="scan'208";a="189497390" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by orsmga007.jf.intel.com with ESMTP; 27 Oct 2019 19:15:37 -0700 From: Wei Yang To: akpm@linux-foundation.org, peterz@infradead.org, walken@google.com, richardw.yang@linux.intel.com, dbueso@suse.de, tglx@linutronix.de Cc: linux-kernel@vger.kernel.org Subject: [Patch v2 1/2] lib/rbtree: set successor's parent unconditionally Date: Mon, 28 Oct 2019 10:14:41 +0800 Message-Id: <20191028021442.5450-1-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 Both in Case 2 and 3, we exchange n and s. This mean no matter whether child2 is NULL or not, successor's parent should be assigned to node's. This patch takes this step out to make it explicit and reduce the ambiguity. Besides, this step reduces some symbol size like rb_erase(). KERN_CONFIG upstream patched OPT_FOR_PERF 877 870 OPT_FOR_SIZE 635 621 Signed-off-by: Wei Yang --- include/linux/rbtree_augmented.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/include/linux/rbtree_augmented.h b/include/linux/rbtree_augmented.h index fdd421b8d9ae..99c42e1a74b8 100644 --- a/include/linux/rbtree_augmented.h +++ b/include/linux/rbtree_augmented.h @@ -283,14 +283,13 @@ __rb_erase_augmented(struct rb_node *node, struct rb_root *root, __rb_change_child(node, successor, tmp, root); if (child2) { - successor->__rb_parent_color = pc; rb_set_parent_color(child2, parent, RB_BLACK); rebalance = NULL; } else { unsigned long pc2 = successor->__rb_parent_color; - successor->__rb_parent_color = pc; rebalance = __rb_is_black(pc2) ? parent : NULL; } + successor->__rb_parent_color = pc; tmp = successor; } -- 2.17.1