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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C660DC10DC1 for ; Thu, 30 Nov 2023 08:46:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344999AbjK3IqM (ORCPT ); Thu, 30 Nov 2023 03:46:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231890AbjK3IqK (ORCPT ); Thu, 30 Nov 2023 03:46:10 -0500 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 84E63A2; Thu, 30 Nov 2023 00:46:15 -0800 (PST) Received: from dggpemm500005.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4SgqRN3BjGzMnZ8; Thu, 30 Nov 2023 16:41:20 +0800 (CST) Received: from [10.69.30.204] (10.69.30.204) by dggpemm500005.china.huawei.com (7.185.36.74) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Thu, 30 Nov 2023 16:46:12 +0800 Subject: Re: [Intel-wired-lan] [PATCH net-next v5 03/14] page_pool: avoid calling no-op externals when possible To: Alexander Lobakin , Christoph Hellwig CC: Paul Menzel , Maciej Fijalkowski , Jesper Dangaard Brouer , Larysa Zaremba , , Alexander Duyck , Ilias Apalodimas , , Eric Dumazet , Michal Kubiak , , David Christensen , Jakub Kicinski , Paolo Abeni , "David S. Miller" References: <20231124154732.1623518-1-aleksander.lobakin@intel.com> <20231124154732.1623518-4-aleksander.lobakin@intel.com> <6bd14aa9-fa65-e4f6-579c-3a1064b2a382@huawei.com> <534e7752-38a9-3e7e-cb04-65789712fb66@huawei.com> <8c6d09be-78d0-436e-a5a6-b94fb094b0b3@intel.com> From: Yunsheng Lin Message-ID: <4814a337-454b-d476-dabe-5035dd6dc51f@huawei.com> Date: Thu, 30 Nov 2023 16:46:11 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <8c6d09be-78d0-436e-a5a6-b94fb094b0b3@intel.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.69.30.204] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500005.china.huawei.com (7.185.36.74) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/11/29 21:17, Alexander Lobakin wrote: > From: Yunsheng Lin > Date: Wed, 29 Nov 2023 11:17:50 +0800 > >> On 2023/11/27 22:32, Alexander Lobakin wrote: >>> >>> Chris, any thoughts on a global flag for skipping DMA syncs ladder? >> >> It seems there was one already in the past: >> >> https://lore.kernel.org/netdev/7c55a4d7-b4aa-25d4-1917-f6f355bd722e@arm.com/T/ > > It addresses a different problem, meaningless indirect calls, while this > one addresses meaningless direct calls :> > When the above gets merged, we could combine these two into one global, > but Eric wasn't active with his patch and I remember there were some > problems, so I wouldn't count on that it will arrive soon. I went through the above patch, It seems to me that there was no fundamental problem that stopping us from implementing it in the dma layer basing on Eric' patch if Eric is no longer interested in working on a newer version? It is just that if we allow every subsystem and driver using dma API doing their own trick of skipping dma sync, then there is less willing to implement it in the dma layer.