From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 352EF43CA8 for ; Fri, 15 Mar 2024 07:07:50 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 29D0D42EC7; Fri, 15 Mar 2024 07:07:50 +0100 (CET) Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) by mails.dpdk.org (Postfix) with ESMTP id 6172342E6B; Fri, 15 Mar 2024 07:06:10 +0100 (CET) Received: from mail.maildlp.com (unknown [172.19.88.234]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4TwtwW1RKfz1h2HB; Fri, 15 Mar 2024 14:03:39 +0800 (CST) Received: from dggpeml500024.china.huawei.com (unknown [7.185.36.10]) by mail.maildlp.com (Postfix) with ESMTPS id D92DD1402CC; Fri, 15 Mar 2024 14:06:07 +0800 (CST) Received: from [10.67.121.161] (10.67.121.161) by dggpeml500024.china.huawei.com (7.185.36.10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Fri, 15 Mar 2024 14:06:07 +0800 Subject: Re: [PATCH v2] dmadev: fix structure alignment To: Wenwu Ma , CC: , References: <20240308053711.1260154-1-wenwux.ma@intel.com> <20240315014331.1376720-1-wenwux.ma@intel.com> From: fengchengwen Message-ID: <096d2161-026c-f89e-c44b-340a3148bccc@huawei.com> Date: Fri, 15 Mar 2024 14:06:07 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20240315014331.1376720-1-wenwux.ma@intel.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.121.161] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpeml500024.china.huawei.com (7.185.36.10) X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org Hi Wenwu, On 2024/3/15 9:43, Wenwu Ma wrote: > The structure rte_dma_dev needs only 8 byte alignment. > This patch replaces __rte_cache_aligned of rte_dma_dev > with __rte_aligned(8). > > Fixes: b36970f2e13e ("dmadev: introduce DMA device library") > Cc: stable@dpdk.org > > Signed-off-by: Wenwu Ma > --- > v2: > - Because of performance drop, adjust the code to > no longer demand cache line alignment Which two versions observed performance drop? And which benchmark observed drop? Could you provide more information? > > --- > lib/dmadev/rte_dmadev_pmd.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/dmadev/rte_dmadev_pmd.h b/lib/dmadev/rte_dmadev_pmd.h > index 58729088ff..b569bb3502 100644 > --- a/lib/dmadev/rte_dmadev_pmd.h > +++ b/lib/dmadev/rte_dmadev_pmd.h > @@ -122,7 +122,7 @@ enum rte_dma_dev_state { > * @internal > * The generic data structure associated with each DMA device. > */ > -struct __rte_cache_aligned rte_dma_dev { > +struct __rte_aligned(8) rte_dma_dev { The DMA fast-path was implemented by struct rte_dma_fp_objs, which is not rte_dma_dev? So why is it a problem here? Thanks > /** Device info which supplied during device initialization. */ > struct rte_device *device; > struct rte_dma_dev_data *data; /**< Pointer to shared device data. */ >