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 71D4CC001DC for ; Sat, 29 Jul 2023 11:40:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231469AbjG2Lk1 (ORCPT ); Sat, 29 Jul 2023 07:40:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229502AbjG2LkZ (ORCPT ); Sat, 29 Jul 2023 07:40:25 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B229E4B; Sat, 29 Jul 2023 04:40:23 -0700 (PDT) Received: from dggpemm500005.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4RCjD60fflzLnvl; Sat, 29 Jul 2023 19:37:42 +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 15.1.2507.27; Sat, 29 Jul 2023 19:40:20 +0800 Subject: Re: [PATCH net-next 2/9] net: skbuff: don't include to To: Alexander Lobakin CC: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Maciej Fijalkowski , Larysa Zaremba , Alexander Duyck , Jesper Dangaard Brouer , Ilias Apalodimas , Simon Horman , , References: <20230727144336.1646454-1-aleksander.lobakin@intel.com> <20230727144336.1646454-3-aleksander.lobakin@intel.com> <5ba84af2-51d1-de5d-14cc-752c08e5371f@intel.com> From: Yunsheng Lin Message-ID: <5830338c-d025-2fb8-46a6-58508493b2cf@huawei.com> Date: Sat, 29 Jul 2023 19:40:19 +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: <5ba84af2-51d1-de5d-14cc-752c08e5371f@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 2023/7/28 21:58, Alexander Lobakin wrote: > From: Yunsheng Lin > Date: Fri, 28 Jul 2023 20:02:51 +0800 > >> On 2023/7/27 22:43, Alexander Lobakin wrote: >>> diff --git a/net/core/skbuff.c b/net/core/skbuff.c >> >> ... >> >>> +bool page_pool_return_skb_page(struct page *page, bool napi_safe) >> >> Still having the 'page_pool_' prefix seems odd here when it is in the >> skbuff.c where most have skb_ or napi_ prefix, is it better to rename >> it to something like napi_return_page_pool_page()? > > Given that how the function that goes next is named, maybe > skb_pp_return_page() (or skb_pp_put_page())? skb_pp_put_page() seems better. And I like napi_pp_put_page() with 'napi_' prefix better as it does not take a skb as parameter and the naming is aligned with the 'napi_safe' parameter. > >> >>> +{ >>> + struct napi_struct *napi; >>> + struct page_pool *pp; >>> + bool allow_direct; >>> + >>> + page = compound_head(page); >>> + >>> + /* page->pp_magic is OR'ed with PP_SIGNATURE after the allocation >>> + * in order to preserve any existing bits, such as bit 0 for the >>> + * head page of compound page and bit 1 for pfmemalloc page, so >>> + * mask those bits for freeing side when doing below checking, >>> + * and page_is_pfmemalloc() is checked in __page_pool_put_page() >>> + * to avoid recycling the pfmemalloc page. >>> + */ >>> + if (unlikely((page->pp_magic & ~0x3UL) != PP_SIGNATURE)) >>> + return false; >>> + >>> + pp = page->pp; >>> + >>> + /* Allow direct recycle if we have reasons to believe that we are >>> + * in the same context as the consumer would run, so there's >>> + * no possible race. >>> + */ >>> + napi = READ_ONCE(pp->p.napi); >>> + allow_direct = napi_safe && napi && >>> + READ_ONCE(napi->list_owner) == smp_processor_id(); >>> + >>> + /* Driver set this to memory recycling info. Reset it on recycle. >>> + * This will *not* work for NIC using a split-page memory model. >>> + * The page will be returned to the pool here regardless of the >>> + * 'flipped' fragment being in use or not. >>> + */ >>> + page_pool_put_full_page(pp, page, allow_direct); >>> + >>> + return true; >>> +} >>> +EXPORT_SYMBOL(page_pool_return_skb_page); >>> + >>> static bool skb_pp_recycle(struct sk_buff *skb, void *data, bool napi_safe) > > (this one) > >>> { >>> if (!IS_ENABLED(CONFIG_PAGE_POOL) || !skb->pp_recycle) We may need the 'IS_ENABLED(CONFIG_PAGE_POOL' checking in the newly moved function too. >>> > > Thanks, > Olek > > . >