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 B2B6AC4332F for ; Mon, 14 Nov 2022 14:16:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236602AbiKNOQu (ORCPT ); Mon, 14 Nov 2022 09:16:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230030AbiKNOQu (ORCPT ); Mon, 14 Nov 2022 09:16:50 -0500 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75EED24F19; Mon, 14 Nov 2022 06:16:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668435409; x=1699971409; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=VWZRwieL0MnAqoIr5PqiCwKsEkjOEOCAdig3LNLeXLs=; b=JInJL6fHxfszv6AIfgcM+yVBL9NrJyJD+ELjabrUwctUT9YV94hK4jjG rdmT+DShEDCxc+h9i8OZ6mLtCaN/FzKYKuOX/lvnr2qjKA1Qm2JId0LSe TV6uNGY4fGQF41iuoln8BR3gICXAXKfYJAG8O0I7ZVTzfPpDHUqrYVPSI Pcxks7ISMZD96XBLVSICsHfzzKwQZsdregvV1xRlokcY/cJ4JU2E4VAqV V4GFdX9VpJrNNxPuZiDKkU8uxhsthrdahxNB4+qN3LcDpqMvVKRaBk+SR 6Snen+Vx1EWoq0musqDu/W7iZQybhlTmeZAg9cj2yC0mMTbb9My9GKrRl Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10531"; a="299494588" X-IronPort-AV: E=Sophos;i="5.96,161,1665471600"; d="scan'208";a="299494588" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2022 06:16:49 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10531"; a="671573894" X-IronPort-AV: E=Sophos;i="5.96,161,1665471600"; d="scan'208";a="671573894" Received: from irvmail001.ir.intel.com ([10.43.11.63]) by orsmga001.jf.intel.com with ESMTP; 14 Nov 2022 06:16:46 -0800 Received: from newjersey.igk.intel.com (newjersey.igk.intel.com [10.102.20.203]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id 2AEEGiQ8012563; Mon, 14 Nov 2022 14:16:44 GMT From: Alexander Lobakin To: Horatiu Vultur Cc: Alexander Lobakin , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, UNGLinuxDriver@microchip.com Subject: Re: [PATCH net-next 1/5] net: lan966x: Add XDP_PACKET_HEADROOM Date: Mon, 14 Nov 2022 15:16:33 +0100 Message-Id: <20221114141633.699268-1-alexandr.lobakin@intel.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221113111559.1028030-2-horatiu.vultur@microchip.com> References: <20221113111559.1028030-1-horatiu.vultur@microchip.com> <20221113111559.1028030-2-horatiu.vultur@microchip.com> MIME-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Horatiu Vultur Date: Sun, 13 Nov 2022 12:15:55 +0100 > Update the page_pool params to allocate XDP_PACKET_HEADROOM space as > headroom for all received frames. > This is needed for when the XDP_TX and XDP_REDIRECT are implemented. > > Signed-off-by: Horatiu Vultur > --- [...] > @@ -466,7 +472,8 @@ static struct sk_buff *lan966x_fdma_rx_get_frame(struct lan966x_rx *rx, > > skb_mark_for_recycle(skb); > > - skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status)); > + skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status) + XDP_PACKET_HEADROOM); > + skb_pull(skb, XDP_PACKET_HEADROOM); These two must be: + skb_reserve(skb, XDP_PACKET_HEADROOM); skb_put(skb, FDMA_DCB_STATUS_BLOCKL(db->status)); i.e. you only need to add reserve, and that's it. It's not only faster, but also moves ::tail, which is essential. > > lan966x_ifh_get_timestamp(skb->data, ×tamp); > [...] > --- a/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c > +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_xdp.c > @@ -44,8 +44,9 @@ int lan966x_xdp_run(struct lan966x_port *port, struct page *page, u32 data_len) > > xdp_init_buff(&xdp, PAGE_SIZE << lan966x->rx.page_order, > &port->xdp_rxq); > - xdp_prepare_buff(&xdp, page_address(page), IFH_LEN_BYTES, > - data_len - IFH_LEN_BYTES, false); > + xdp_prepare_buff(&xdp, page_address(page), > + IFH_LEN_BYTES + XDP_PACKET_HEADROOM, > + data_len - IFH_LEN_BYTES - XDP_PACKET_HEADROOM, false); Are you sure you need to substract %XDP_PACKET_HEADROOM from @data_len? I think @data_len is the frame length, so headroom is not included? > act = bpf_prog_run_xdp(xdp_prog, &xdp); > switch (act) { > case XDP_PASS: > -- > 2.38.0 Thanks, Olek