From nobody Fri Sep 20 12:48:39 2024 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 92210CA0EC3 for ; Tue, 12 Sep 2023 08:35:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232760AbjILIfJ (ORCPT ); Tue, 12 Sep 2023 04:35:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232762AbjILIe4 (ORCPT ); Tue, 12 Sep 2023 04:34:56 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC8FB10C8; Tue, 12 Sep 2023 01:34:51 -0700 (PDT) Received: from dggpemm500005.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4RlGz73HGrzVkf4; Tue, 12 Sep 2023 16:32:03 +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 15.1.2507.31; Tue, 12 Sep 2023 16:34:49 +0800 From: Yunsheng Lin To: , , CC: , , Yunsheng Lin , Lorenzo Bianconi , Alexander Duyck , Liang Chen , Alexander Lobakin , Jesper Dangaard Brouer , Ilias Apalodimas , Eric Dumazet Subject: [PATCH net-next v8 4/6] page_pool: introduce page_pool[_cache]_alloc() API Date: Tue, 12 Sep 2023 16:31:23 +0800 Message-ID: <20230912083126.65484-5-linyunsheng@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20230912083126.65484-1-linyunsheng@huawei.com> References: <20230912083126.65484-1-linyunsheng@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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 Content-Type: text/plain; charset="utf-8" Currently page pool supports the below use cases: use case 1: allocate page without page splitting using page_pool_alloc_pages() API if the driver knows that the memory it need is always bigger than half of the page allocated from page pool. use case 2: allocate page frag with page splitting using page_pool_alloc_frag() API if the driver knows that the memory it need is always smaller than or equal to the half of the page allocated from page pool. There is emerging use case [1] & [2] that is a mix of the above two case: the driver doesn't know the size of memory it need beforehand, so the driver may use something like below to allocate memory with least memory utilization and performance penalty: if (size << 1 > max_size) page =3D page_pool_alloc_pages(); else page =3D page_pool_alloc_frag(); To avoid the driver doing something like above, add the page_pool[_cache]_alloc() API to support the above use case, and update the true size of memory that is acctually allocated by updating '*size' back to the driver in order to avoid exacerbating truesize underestimate problem. Rename page_pool_free() which is used in the destroy process to __page_pool_destroy() to avoid confusion with the newly added API. 1. https://lore.kernel.org/all/d3ae6bd3537fbce379382ac6a42f67e22f27ece2.168= 3896626.git.lorenzo@kernel.org/ 2. https://lore.kernel.org/all/20230526054621.18371-3-liangchen.linux@gmail= .com/ Signed-off-by: Yunsheng Lin CC: Lorenzo Bianconi CC: Alexander Duyck CC: Liang Chen CC: Alexander Lobakin --- include/net/page_pool/helpers.h | 65 +++++++++++++++++++++++++++++++++ net/core/page_pool.c | 4 +- 2 files changed, 67 insertions(+), 2 deletions(-) diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helper= s.h index 0ec81b91bed8..c0e6c7d1b219 100644 --- a/include/net/page_pool/helpers.h +++ b/include/net/page_pool/helpers.h @@ -82,6 +82,65 @@ static inline struct page *page_pool_dev_alloc_frag(stru= ct page_pool *pool, return page_pool_alloc_frag(pool, offset, size, gfp); } =20 +static inline struct page *page_pool_alloc(struct page_pool *pool, + unsigned int *offset, + unsigned int *size, gfp_t gfp) +{ + unsigned int max_size =3D PAGE_SIZE << pool->p.order; + struct page *page; + + if ((*size << 1) > max_size) { + *size =3D max_size; + *offset =3D 0; + return page_pool_alloc_pages(pool, gfp); + } + + page =3D page_pool_alloc_frag(pool, offset, *size, gfp); + if (unlikely(!page)) + return NULL; + + /* There is very likely not enough space for another frag, so append the + * remaining size to the current frag to avoid truesize underestimate + * problem. + */ + if (pool->frag_offset + *size > max_size) { + *size =3D max_size - *offset; + pool->frag_offset =3D max_size; + } + + return page; +} + +static inline struct page *page_pool_dev_alloc(struct page_pool *pool, + unsigned int *offset, + unsigned int *size) +{ + gfp_t gfp =3D (GFP_ATOMIC | __GFP_NOWARN); + + return page_pool_alloc(pool, offset, size, gfp); +} + +static inline void *page_pool_cache_alloc(struct page_pool *pool, + unsigned int *size, gfp_t gfp) +{ + unsigned int offset; + struct page *page; + + page =3D page_pool_alloc(pool, &offset, size, gfp); + if (unlikely(!page)) + return NULL; + + return page_address(page) + offset; +} + +static inline void *page_pool_dev_cache_alloc(struct page_pool *pool, + unsigned int *size) +{ + gfp_t gfp =3D (GFP_ATOMIC | __GFP_NOWARN); + + return page_pool_cache_alloc(pool, size, gfp); +} + /** * page_pool_get_dma_dir() - Retrieve the stored DMA direction. * @pool: pool from which page was allocated @@ -222,6 +281,12 @@ static inline void page_pool_recycle_direct(struct pag= e_pool *pool, #define PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA \ (sizeof(dma_addr_t) > sizeof(unsigned long)) =20 +static inline void page_pool_cache_free(struct page_pool *pool, void *data, + bool allow_direct) +{ + page_pool_put_page(pool, virt_to_head_page(data), -1, allow_direct); +} + /** * page_pool_get_dma_addr() - Retrieve the stored DMA address. * @page: page allocated from a page pool diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 1927b9c36c23..74106f6d8f73 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -809,7 +809,7 @@ static void page_pool_empty_ring(struct page_pool *pool) } } =20 -static void page_pool_free(struct page_pool *pool) +static void __page_pool_destroy(struct page_pool *pool) { if (pool->disconnect) pool->disconnect(pool); @@ -860,7 +860,7 @@ static int page_pool_release(struct page_pool *pool) page_pool_scrub(pool); inflight =3D page_pool_inflight(pool); if (!inflight) - page_pool_free(pool); + __page_pool_destroy(pool); =20 return inflight; } --=20 2.33.0