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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 EB1DBC433ED for ; Wed, 12 May 2021 13:12:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9CEE161260 for ; Wed, 12 May 2021 13:12:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231650AbhELNNV (ORCPT ); Wed, 12 May 2021 09:13:21 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:2569 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231428AbhELNNV (ORCPT ); Wed, 12 May 2021 09:13:21 -0400 Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4FgFVz4gYXzsRJs; Wed, 12 May 2021 21:09:31 +0800 (CST) Received: from [127.0.0.1] (10.174.177.72) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.498.0; Wed, 12 May 2021 21:12:09 +0800 Subject: Re: [PATCH v2 2/2] RDMA/cm: Optimise rbtree searching To: Jason Gunthorpe CC: Doug Ledford , Leon Romanovsky , linux-rdma References: <20210512100537.6273-1-thunder.leizhen@huawei.com> <20210512100537.6273-3-thunder.leizhen@huawei.com> <20210512125006.GE1096940@ziepe.ca> From: "Leizhen (ThunderTown)" Message-ID: Date: Wed, 12 May 2021 21:12:08 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20210512125006.GE1096940@ziepe.ca> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.177.72] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 2021/5/12 20:50, Jason Gunthorpe wrote: > On Wed, May 12, 2021 at 06:05:37PM +0800, Zhen Lei wrote: >> static struct cm_id_private *cm_find_listen(struct ib_device *device, >> @@ -686,22 +687,23 @@ static struct cm_id_private *cm_find_listen(struct ib_device *device, >> >> while (node) { >> cm_id_priv = rb_entry(node, struct cm_id_private, service_node); >> - if ((cm_id_priv->id.service_mask & service_id) == >> - cm_id_priv->id.service_id && >> - (cm_id_priv->id.device == device)) { >> - refcount_inc(&cm_id_priv->refcount); >> - return cm_id_priv; >> - } >> + >> if (device < cm_id_priv->id.device) >> node = node->rb_left; >> else if (device > cm_id_priv->id.device) >> node = node->rb_right; >> + else if ((cm_id_priv->id.service_mask & service_id) == cm_id_priv->id.service_id) >> + goto found; >> else if (be64_lt(service_id, cm_id_priv->id.service_id)) >> node = node->rb_left; >> else >> node = node->rb_right; >> } > > This is not the pattern I showed you. Drop the first patch and rely on > the implicit equality in the final else. Do you mean treate the "found" process as the else branch? But ((cm_id_priv->id.service_mask & service_id) == cm_id_priv->id.service_id) is different from (service_id == cm_id_priv->id.service_id)，I'm just worried that it might change the original logic. > > Jason > > . >