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 C4744C3527E for ; Tue, 5 Apr 2022 12:02:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381950AbiDEMAL (ORCPT ); Tue, 5 Apr 2022 08:00:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245094AbiDEIxO (ORCPT ); Tue, 5 Apr 2022 04:53:14 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D1A7EA; Tue, 5 Apr 2022 01:51:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AF63D61504; Tue, 5 Apr 2022 08:51:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E7A6C385A1; Tue, 5 Apr 2022 08:51:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649148676; bh=opiEEy8Zkh9teV55fjvoiiH/gqsoGMYbbK0t9H7hr2E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nGQL6fMC5CDD+WrSqraUK+qcoxj01E5NrV2QaRSiSXWyoxlj21b7e+BPHYaS8JJj1 cuTAb9zpgqfpWRohw0zixbM6P4RRK+wB0TGQRkdcTCY6F3UvffvgnSpWSaHwWS+K6t HVjh+8o0oTJwWwJFPnaJYsYmFd+hbgcrrA0SXgME= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Lobakin , Michal Swiatkowski , Nechama Kraus , Tony Nguyen , Sasha Levin Subject: [PATCH 5.16 0442/1017] igc: dont reserve excessive XDP_PACKET_HEADROOM on XSK Rx to skb Date: Tue, 5 Apr 2022 09:22:35 +0200 Message-Id: <20220405070407.415901628@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexander Lobakin [ Upstream commit f9e61d365bafdee40fe2586fc6be490c3e824dad ] {__,}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_construct_skb(). Fixes: fc9df2a0b520 ("igc: Enable RX via AF_XDP zero-copy") Signed-off-by: Alexander Lobakin Reviewed-by: Michal Swiatkowski Tested-by: Nechama Kraus Signed-off-by: Tony Nguyen Signed-off-by: Sasha Levin --- 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 d83e665b3a4f..a156738dc9b6 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -2435,19 +2435,20 @@ 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); -- 2.34.1