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 EEF43C77B7A for ; Mon, 29 May 2023 09:30:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231650AbjE2Jav (ORCPT ); Mon, 29 May 2023 05:30:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230153AbjE2Jao (ORCPT ); Mon, 29 May 2023 05:30:44 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 936559E; Mon, 29 May 2023 02:30:42 -0700 (PDT) Received: from dggpemm500005.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4QV9Fv1NsNzLmX5; Mon, 29 May 2023 17:29:07 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) 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 15.1.2507.23; Mon, 29 May 2023 17:30:40 +0800 From: Yunsheng Lin To: , , CC: , , Yunsheng Lin , Lorenzo Bianconi , Alexander Duyck , Jesper Dangaard Brouer , Ilias Apalodimas , Eric Dumazet Subject: [PATCH net-next v2 2/3] page_pool: support non-frag page for page_pool_alloc_frag() Date: Mon, 29 May 2023 17:28:39 +0800 Message-ID: <20230529092840.40413-3-linyunsheng@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20230529092840.40413-1-linyunsheng@huawei.com> References: <20230529092840.40413-1-linyunsheng@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) 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 There is performance penalty with using page frag support when user requests a larger frag size and a page only supports one frag user, see [1]. It seems like user may request different frag size depending on the mtu and packet size, provide an option to allocate non-frag page when a whole page is not able to hold two frags, so that user has a unified interface for the memory allocation with least memory utilization and performance penalty. 1. https://lore.kernel.org/netdev/ZEU+vospFdm08IeE@localhost.localdomain/ Signed-off-by: Yunsheng Lin CC: Lorenzo Bianconi CC: Alexander Duyck --- net/core/page_pool.c | 47 +++++++++++++++++++++++++++----------------- 1 file changed, 29 insertions(+), 18 deletions(-) diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 0868aa8f6323..e84ec6eabefd 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -699,14 +699,27 @@ struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int max_size = PAGE_SIZE << pool->p.order; struct page *page = pool->frag_page; - if (WARN_ON(!(pool->p.flags & PP_FLAG_PAGE_FRAG) || - size > max_size)) + if (unlikely(size > max_size)) return NULL; + if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT) { + *offset = 0; + return page_pool_alloc_pages(pool, gfp); + } + size = ALIGN(size, dma_get_cache_alignment()); - *offset = pool->frag_offset; - if (page && *offset + size > max_size) { + if (page) { + *offset = pool->frag_offset; + + if (*offset + size <= max_size) { + pool->frag_users++; + pool->frag_offset = *offset + size; + alloc_stat_inc(pool, fast); + return page; + } + + pool->frag_page = NULL; page = page_pool_drain_frag(pool, page); if (page) { alloc_stat_inc(pool, fast); @@ -714,26 +727,24 @@ struct page *page_pool_alloc_frag(struct page_pool *pool, } } - if (!page) { - page = page_pool_alloc_pages(pool, gfp); - if (unlikely(!page)) { - pool->frag_page = NULL; - return NULL; - } - - pool->frag_page = page; + page = page_pool_alloc_pages(pool, gfp); + if (unlikely(!page)) + return NULL; frag_reset: - pool->frag_users = 1; + /* return page as non-frag page if a page is not able to + * hold two frags for the current requested size. + */ + if (unlikely(size << 1 > max_size)) { *offset = 0; - pool->frag_offset = size; - page_pool_fragment_page(page, BIAS_MAX); return page; } - pool->frag_users++; - pool->frag_offset = *offset + size; - alloc_stat_inc(pool, fast); + pool->frag_page = page; + pool->frag_users = 1; + *offset = 0; + pool->frag_offset = size; + page_pool_fragment_page(page, BIAS_MAX); return page; } EXPORT_SYMBOL(page_pool_alloc_frag); -- 2.33.0