From patchwork Tue Nov 10 15:37:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Bianconi X-Patchwork-Id: 11894657 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1A98C5517A for ; Tue, 10 Nov 2020 15:38:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E2A9207E8 for ; Tue, 10 Nov 2020 15:38:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="UQSKXGgr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732274AbgKJPiU (ORCPT ); Tue, 10 Nov 2020 10:38:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:35778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729794AbgKJPiU (ORCPT ); Tue, 10 Nov 2020 10:38:20 -0500 Received: from lore-desk.redhat.com (unknown [151.66.8.153]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1ED4520795; Tue, 10 Nov 2020 15:38:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605022699; bh=UWielLYv/edECihcwlk+zw3lTDGnPV4D8p89gUmU3l4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UQSKXGgrLOETT6exUDaX3VzTJE12rIzHjG780Iw2cxbgIoFf7HUniy5D5kNVwgwWX Af4wwuri6QrPpCKo4czZ35QB3+TbFxfrcy72OBQ0SLr1sorHLEY47AThyk6MfYs5CT 0Mpq7zjTwCCZf0ENaUJAIId3PNOGsryQ9tjv4aH4= From: Lorenzo Bianconi To: netdev@vger.kernel.org Cc: bpf@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, lorenzo.bianconi@redhat.com, brouer@redhat.com, ilias.apalodimas@linaro.org Subject: [PATCH v5 net-nex 1/5] net: xdp: introduce bulking for xdp tx return path Date: Tue, 10 Nov 2020 16:37:56 +0100 Message-Id: <809b608c86142afe88572fae4dc4e21ac9899f7c.1605020963.git.lorenzo@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org XDP bulk APIs introduce a defer/flush mechanism to return pages belonging to the same xdp_mem_allocator object (identified via the mem.id field) in bulk to optimize I-cache and D-cache since xdp_return_frame is usually run inside the driver NAPI tx completion loop. The bulk queue size is set to 16 to be aligned to how XDP_REDIRECT bulking works. The bulk is flushed when it is full or when mem.id changes. xdp_frame_bulk is usually stored/allocated on the function call-stack to avoid locking penalties. Current implementation considers only page_pool memory model. Suggested-by: Jesper Dangaard Brouer Co-developed-by: Jesper Dangaard Brouer Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Lorenzo Bianconi --- include/net/xdp.h | 17 +++++++++++++- net/core/xdp.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 75 insertions(+), 1 deletion(-) diff --git a/include/net/xdp.h b/include/net/xdp.h index 3814fb631d52..7d48b2ae217a 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -104,6 +104,18 @@ struct xdp_frame { struct net_device *dev_rx; /* used by cpumap */ }; +#define XDP_BULK_QUEUE_SIZE 16 +struct xdp_frame_bulk { + int count; + void *xa; + void *q[XDP_BULK_QUEUE_SIZE]; +}; + +static __always_inline void xdp_frame_bulk_init(struct xdp_frame_bulk *bq) +{ + /* bq->count will be zero'ed when bq->xa gets updated */ + bq->xa = NULL; +} static inline struct skb_shared_info * xdp_get_shared_info_from_frame(struct xdp_frame *frame) @@ -194,6 +206,9 @@ struct xdp_frame *xdp_convert_buff_to_frame(struct xdp_buff *xdp) void xdp_return_frame(struct xdp_frame *xdpf); void xdp_return_frame_rx_napi(struct xdp_frame *xdpf); void xdp_return_buff(struct xdp_buff *xdp); +void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq); +void xdp_return_frame_bulk(struct xdp_frame *xdpf, + struct xdp_frame_bulk *bq); /* When sending xdp_frame into the network stack, then there is no * return point callback, which is needed to release e.g. DMA-mapping @@ -245,6 +260,6 @@ bool xdp_attachment_flags_ok(struct xdp_attachment_info *info, void xdp_attachment_setup(struct xdp_attachment_info *info, struct netdev_bpf *bpf); -#define DEV_MAP_BULK_SIZE 16 +#define DEV_MAP_BULK_SIZE XDP_BULK_QUEUE_SIZE #endif /* __LINUX_NET_XDP_H__ */ diff --git a/net/core/xdp.c b/net/core/xdp.c index 48aba933a5a8..bbaee7fdd44f 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -380,6 +380,65 @@ void xdp_return_frame_rx_napi(struct xdp_frame *xdpf) } EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi); +/* XDP bulk APIs introduce a defer/flush mechanism to return + * pages belonging to the same xdp_mem_allocator object + * (identified via the mem.id field) in bulk to optimize + * I-cache and D-cache. + * The bulk queue size is set to 16 to be aligned to how + * XDP_REDIRECT bulking works. The bulk is flushed when + * it is full or when mem.id changes. + * xdp_frame_bulk is usually stored/allocated on the function + * call-stack to avoid locking penalties. + */ +void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq) +{ + struct xdp_mem_allocator *xa = bq->xa; + int i; + + if (unlikely(!xa)) + return; + + for (i = 0; i < bq->count; i++) { + struct page *page = virt_to_head_page(bq->q[i]); + + page_pool_put_full_page(xa->page_pool, page, false); + } + /* bq->xa is not cleared to save lookup, if mem.id same in next bulk */ + bq->count = 0; +} +EXPORT_SYMBOL_GPL(xdp_flush_frame_bulk); + +/* Must be called with rcu_read_lock held */ +void xdp_return_frame_bulk(struct xdp_frame *xdpf, + struct xdp_frame_bulk *bq) +{ + struct xdp_mem_info *mem = &xdpf->mem; + struct xdp_mem_allocator *xa; + + if (mem->type != MEM_TYPE_PAGE_POOL) { + __xdp_return(xdpf->data, &xdpf->mem, false); + return; + } + + xa = bq->xa; + if (unlikely(!xa)) { + xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); + bq->count = 0; + bq->xa = xa; + } + + if (bq->count == XDP_BULK_QUEUE_SIZE) + xdp_flush_frame_bulk(bq); + + if (unlikely(mem->id != xa->mem.id)) { + xdp_flush_frame_bulk(bq); + bq->xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params); + } + + bq->q[bq->count++] = xdpf->data; +} +EXPORT_SYMBOL_GPL(xdp_return_frame_bulk); + void xdp_return_buff(struct xdp_buff *xdp) { __xdp_return(xdp->data, &xdp->rxq->mem, true);