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GET /api/patches/1183254/?format=api
{ "id": 1183254, "url": "http://patchwork.ozlabs.org/api/patches/1183254/?format=api", "web_url": "http://patchwork.ozlabs.org/project/intel-wired-lan/patch/20191024081125.6711-8-anthony.l.nguyen@intel.com/", "project": { "id": 46, "url": "http://patchwork.ozlabs.org/api/projects/46/?format=api", "name": "Intel Wired Ethernet development", "link_name": "intel-wired-lan", "list_id": "intel-wired-lan.osuosl.org", "list_email": "intel-wired-lan@osuosl.org", "web_url": "", "scm_url": "", "webscm_url": "", "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20191024081125.6711-8-anthony.l.nguyen@intel.com>", "list_archive_url": null, "date": "2019-10-24T08:11:24", "name": "[S30,v3,8/9] ice: add build_skb() support", "commit_ref": null, "pull_url": null, "state": "accepted", "archived": false, "hash": "141c6b8d04f6b09673ca45d92dea1151a820d1da", "submitter": { "id": 68875, "url": "http://patchwork.ozlabs.org/api/people/68875/?format=api", "name": "Tony Nguyen", "email": "anthony.l.nguyen@intel.com" }, "delegate": { "id": 68, "url": "http://patchwork.ozlabs.org/api/users/68/?format=api", "username": "jtkirshe", "first_name": "Jeff", "last_name": "Kirsher", "email": "jeffrey.t.kirsher@intel.com" }, "mbox": "http://patchwork.ozlabs.org/project/intel-wired-lan/patch/20191024081125.6711-8-anthony.l.nguyen@intel.com/mbox/", "series": [ { "id": 138433, "url": "http://patchwork.ozlabs.org/api/series/138433/?format=api", "web_url": "http://patchwork.ozlabs.org/project/intel-wired-lan/list/?series=138433", "date": "2019-10-24T08:11:25", "name": "[S30,v3,1/9] ice: Introduce ice_base.c", "version": 3, "mbox": "http://patchwork.ozlabs.org/series/138433/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/1183254/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/1183254/checks/", "tags": {}, "related": [], "headers": { "Return-Path": "<intel-wired-lan-bounces@osuosl.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "intel-wired-lan@lists.osuosl.org" ], "Delivered-To": [ "patchwork-incoming@bilbo.ozlabs.org", "intel-wired-lan@lists.osuosl.org" ], "Authentication-Results": [ "ozlabs.org; spf=pass (sender SPF authorized)\n\tsmtp.mailfrom=osuosl.org (client-ip=140.211.166.137;\n\thelo=fraxinus.osuosl.org;\n\tenvelope-from=intel-wired-lan-bounces@osuosl.org;\n\treceiver=<UNKNOWN>)", "ozlabs.org;\n\tdmarc=fail (p=none dis=none) header.from=intel.com" ], "Received": [ "from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256\n\tbits)) (No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 46zY2X08lwz9sPh\n\tfor <incoming@patchwork.ozlabs.org>;\n\tFri, 25 Oct 2019 03:42:59 +1100 (AEDT)", "from localhost (localhost [127.0.0.1])\n\tby fraxinus.osuosl.org (Postfix) with ESMTP id 928F786985;\n\tThu, 24 Oct 2019 16:42:58 +0000 (UTC)", "from fraxinus.osuosl.org ([127.0.0.1])\n\tby localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024)\n\twith ESMTP id hN0FZOhmWqrG; Thu, 24 Oct 2019 16:42:57 +0000 (UTC)", "from ash.osuosl.org (ash.osuosl.org [140.211.166.34])\n\tby fraxinus.osuosl.org (Postfix) with ESMTP id EAC7986990;\n\tThu, 24 Oct 2019 16:42:57 +0000 (UTC)", "from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133])\n\tby ash.osuosl.org (Postfix) with ESMTP id E7DE91BF860\n\tfor <intel-wired-lan@lists.osuosl.org>;\n\tThu, 24 Oct 2019 16:42:56 +0000 (UTC)", "from localhost (localhost [127.0.0.1])\n\tby hemlock.osuosl.org (Postfix) with ESMTP id DBF5C8829F\n\tfor <intel-wired-lan@lists.osuosl.org>;\n\tThu, 24 Oct 2019 16:42:56 +0000 (UTC)", "from hemlock.osuosl.org ([127.0.0.1])\n\tby localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024)\n\twith ESMTP id IDvRhY2H-uTg for <intel-wired-lan@lists.osuosl.org>;\n\tThu, 24 Oct 2019 16:42:56 +0000 (UTC)", "from mga06.intel.com (mga06.intel.com [134.134.136.31])\n\tby hemlock.osuosl.org (Postfix) with ESMTPS id 3A6C988235\n\tfor <intel-wired-lan@lists.osuosl.org>;\n\tThu, 24 Oct 2019 16:42:56 +0000 (UTC)", "from orsmga002.jf.intel.com ([10.7.209.21])\n\tby orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384;\n\t24 Oct 2019 09:41:54 -0700", "from unknown (HELO localhost.jf.intel.com) ([10.166.244.174])\n\tby orsmga002.jf.intel.com with ESMTP; 24 Oct 2019 09:41:53 -0700" ], "X-Virus-Scanned": [ "amavisd-new at osuosl.org", "amavisd-new at osuosl.org" ], "X-Greylist": "domain auto-whitelisted by SQLgrey-1.7.6", "X-Amp-Result": "SKIPPED(no attachment in message)", "X-Amp-File-Uploaded": "False", "X-ExtLoop1": "1", "X-IronPort-AV": "E=Sophos;i=\"5.68,225,1569308400\"; d=\"scan'208\";a=\"210438734\"", "From": "Tony Nguyen <anthony.l.nguyen@intel.com>", "To": "intel-wired-lan@lists.osuosl.org", "Date": "Thu, 24 Oct 2019 01:11:24 -0700", "Message-Id": "<20191024081125.6711-8-anthony.l.nguyen@intel.com>", "X-Mailer": "git-send-email 2.20.1", "In-Reply-To": "<20191024081125.6711-1-anthony.l.nguyen@intel.com>", "References": "<20191024081125.6711-1-anthony.l.nguyen@intel.com>", "MIME-Version": "1.0", "Subject": "[Intel-wired-lan] [PATCH S30 v3 8/9] ice: add build_skb() support", "X-BeenThere": "intel-wired-lan@osuosl.org", "X-Mailman-Version": "2.1.29", "Precedence": "list", "List-Id": "Intel Wired Ethernet Linux Kernel Driver Development\n\t<intel-wired-lan.osuosl.org>", "List-Unsubscribe": "<https://lists.osuosl.org/mailman/options/intel-wired-lan>, \n\t<mailto:intel-wired-lan-request@osuosl.org?subject=unsubscribe>", "List-Archive": "<http://lists.osuosl.org/pipermail/intel-wired-lan/>", "List-Post": "<mailto:intel-wired-lan@osuosl.org>", "List-Help": "<mailto:intel-wired-lan-request@osuosl.org?subject=help>", "List-Subscribe": "<https://lists.osuosl.org/mailman/listinfo/intel-wired-lan>, \n\t<mailto:intel-wired-lan-request@osuosl.org?subject=subscribe>", "Content-Type": "text/plain; charset=\"us-ascii\"", "Content-Transfer-Encoding": "7bit", "Errors-To": "intel-wired-lan-bounces@osuosl.org", "Sender": "\"Intel-wired-lan\" <intel-wired-lan-bounces@osuosl.org>" }, "content": "From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>\n\nDriver is now prepared for building the skb around the existing Rx\nbuffer, so introduce the ice_build_skb responsible for it. Make use of\nXDP's data_meta as well.\n\nI've observed around 30% less CPU consumption with build_skb Rx path, in\ncomparison to legacy Rx. What stands behind such result is the avoidance\nof flow_dissector (which we were diving into via eth_get_headlen) and no\nmemcpy calls.\n\nSigned-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>\n---\n drivers/net/ethernet/intel/ice/ice_txrx.c | 60 ++++++++++++++++++++++-\n 1 file changed, 59 insertions(+), 1 deletion(-)", "diff": "diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c\nindex 71c4464934af..8e3a69d3884d 100644\n--- a/drivers/net/ethernet/intel/ice/ice_txrx.c\n+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c\n@@ -790,6 +790,60 @@ ice_get_rx_buf(struct ice_ring *rx_ring, struct sk_buff **skb,\n \treturn rx_buf;\n }\n \n+/**\n+ * ice_build_skb - Build skb around an existing buffer\n+ * @rx_ring: Rx descriptor ring to transact packets on\n+ * @rx_buf: Rx buffer to pull data from\n+ * @xdp: xdp_buff pointing to the data\n+ *\n+ * This function builds an skb around an existing Rx buffer, taking care\n+ * to set up the skb correctly and avoid any memcpy overhead.\n+ */\n+static struct sk_buff *\n+ice_build_skb(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf,\n+\t struct xdp_buff *xdp)\n+{\n+\tunsigned int metasize = xdp->data - xdp->data_meta;\n+#if (PAGE_SIZE < 8192)\n+\tunsigned int truesize = ice_rx_pg_size(rx_ring) / 2;\n+#else\n+\tunsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +\n+\t\t\t\tSKB_DATA_ALIGN(xdp->data_end -\n+\t\t\t\t\t xdp->data_hard_start);\n+#endif\n+\tstruct sk_buff *skb;\n+\n+\t/* Prefetch first cache line of first page. If xdp->data_meta\n+\t * is unused, this points exactly as xdp->data, otherwise we\n+\t * likely have a consumer accessing first few bytes of meta\n+\t * data, and then actual data.\n+\t */\n+\tprefetch(xdp->data_meta);\n+#if L1_CACHE_BYTES < 128\n+\tprefetch((void *)(xdp->data + L1_CACHE_BYTES));\n+#endif\n+\t/* build an skb around the page buffer */\n+\tskb = build_skb(xdp->data_hard_start, truesize);\n+\tif (unlikely(!skb))\n+\t\treturn NULL;\n+\n+\t/* must to record Rx queue, otherwise OS features such as\n+\t * symmetric queue won't work\n+\t */\n+\tskb_record_rx_queue(skb, rx_ring->q_index);\n+\n+\t/* update pointers within the skb to store the data */\n+\tskb_reserve(skb, xdp->data - xdp->data_hard_start);\n+\t__skb_put(skb, xdp->data_end - xdp->data);\n+\tif (metasize)\n+\t\tskb_metadata_set(skb, metasize);\n+\n+\t/* buffer is used by skb, update page_offset */\n+\tice_rx_buf_adjust_pg_offset(rx_buf, truesize);\n+\n+\treturn skb;\n+}\n+\n /**\n * ice_construct_skb - Allocate skb and populate it\n * @rx_ring: Rx descriptor ring to transact packets on\n@@ -996,12 +1050,14 @@ static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)\n \t\tif (!size) {\n \t\t\txdp.data = NULL;\n \t\t\txdp.data_end = NULL;\n+\t\t\txdp.data_hard_start = NULL;\n+\t\t\txdp.data_meta = NULL;\n \t\t\tgoto construct_skb;\n \t\t}\n \n \t\txdp.data = page_address(rx_buf->page) + rx_buf->page_offset;\n \t\txdp.data_hard_start = xdp.data - ice_rx_offset(rx_ring);\n-\t\txdp_set_data_meta_invalid(&xdp);\n+\t\txdp.data_meta = xdp.data;\n \t\txdp.data_end = xdp.data + size;\n \n \t\trcu_read_lock();\n@@ -1038,6 +1094,8 @@ static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)\n construct_skb:\n \t\tif (skb)\n \t\t\tice_add_rx_frag(rx_ring, rx_buf, skb, size);\n+\t\telse if (ice_ring_uses_build_skb(rx_ring))\n+\t\t\tskb = ice_build_skb(rx_ring, rx_buf, &xdp);\n \t\telse\n \t\t\tskb = ice_construct_skb(rx_ring, rx_buf, &xdp);\n \n", "prefixes": [ "S30", "v3", "8/9" ] }