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 45C52C433F5 for ; Wed, 8 Dec 2021 14:07:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234821AbhLHOLP (ORCPT ); Wed, 8 Dec 2021 09:11:15 -0500 Received: from mga11.intel.com ([192.55.52.93]:15236 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231363AbhLHOLL (ORCPT ); Wed, 8 Dec 2021 09:11:11 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10191"; a="235346827" X-IronPort-AV: E=Sophos;i="5.88,189,1635231600"; d="scan'208";a="235346827" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2021 06:07:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,189,1635231600"; d="scan'208";a="658296416" Received: from irvmail001.ir.intel.com ([10.43.11.63]) by fmsmga001.fm.intel.com with ESMTP; 08 Dec 2021 06:07:35 -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 1B8E7Qui009548; Wed, 8 Dec 2021 14:07:33 GMT From: Alexander Lobakin To: intel-wired-lan@lists.osuosl.org Cc: Alexander Lobakin , Jesse Brandeburg , Tony Nguyen , "David S. Miller" , Jakub Kicinski , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Maciej Fijalkowski , Michal Swiatkowski , Jithu Joseph , Martin KaFai Lau , Song Liu , KP Singh , Yonghong Song , Andrii Nakryiko , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH v4 net-next 6/9] igc: don't reserve excessive XDP_PACKET_HEADROOM on XSK Rx to skb Date: Wed, 8 Dec 2021 15:06:59 +0100 Message-Id: <20211208140702.642741-7-alexandr.lobakin@intel.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211208140702.642741-1-alexandr.lobakin@intel.com> References: <20211208140702.642741-1-alexandr.lobakin@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org {__,}napi_alloc_skb() allocates and reserves additional NET_SKB_PAD + NET_IP_ALIGN for any skb. OTOH, igc_construct_skb_zc() currently allocates and reserves additional `xdp->data_meta - xdp->data_hard_start`, which is about XDP_PACKET_HEADROOM for XSK frames. There's no need for that at all as the frame is post-XDP and will go only to the networking stack core. Pass the size of the actual data only (+ meta) to __napi_alloc_skb() and don't reserve anything. This will give enough headroom for stack processing. Also, net_prefetch() xdp->data_meta and align the copy size to speed-up memcpy() a little and better match igc_costruct_skb(). Fixes: fc9df2a0b520 ("igc: Enable RX via AF_XDP zero-copy") Signed-off-by: Alexander Lobakin Reviewed-by: Michal Swiatkowski --- drivers/net/ethernet/intel/igc/igc_main.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 142c57b7a451..a2e8d43be3a1 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -2446,19 +2446,20 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget) static struct sk_buff *igc_construct_skb_zc(struct igc_ring *ring, struct xdp_buff *xdp) { + unsigned int totalsize = xdp->data_end - xdp->data_meta; unsigned int metasize = xdp->data - xdp->data_meta; - unsigned int datasize = xdp->data_end - xdp->data; - unsigned int totalsize = metasize + datasize; struct sk_buff *skb; - skb = __napi_alloc_skb(&ring->q_vector->napi, - xdp->data_end - xdp->data_hard_start, + net_prefetch(xdp->data_meta); + + skb = __napi_alloc_skb(&ring->q_vector->napi, totalsize, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!skb)) return NULL; - skb_reserve(skb, xdp->data_meta - xdp->data_hard_start); - memcpy(__skb_put(skb, totalsize), xdp->data_meta, totalsize); + memcpy(__skb_put(skb, totalsize), xdp->data_meta, + ALIGN(totalsize, sizeof(long))); + if (metasize) { skb_metadata_set(skb, metasize); __skb_pull(skb, metasize); -- 2.33.1