From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753028AbdEAVgA (ORCPT ); Mon, 1 May 2017 17:36:00 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:58420 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752937AbdEAVfp (ORCPT ); Mon, 1 May 2017 17:35:45 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eugenia Emantayev , Saeed Mahameed Subject: [PATCH 4.10 34/62] net/mlx5e: Fix small packet threshold Date: Mon, 1 May 2017 14:34:47 -0700 Message-Id: <20170501212732.094510422@linuxfoundation.org> X-Mailer: git-send-email 2.12.2 In-Reply-To: <20170501212730.774855694@linuxfoundation.org> References: <20170501212730.774855694@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eugenia Emantayev [ Upstream commit cbad8cddb6ed7ef3a5f0a9a70f1711d4d7fb9a8f ] RX packet headers are meant to be contained in SKB linear part, and chose a threshold of 128. It turns out this is not enough, i.e. for IPv6 packet over VxLAN. In this case, UDP/IPv4 needs 42 bytes, GENEVE header is 8 bytes, and 86 bytes for TCP/IPv6. In total 136 bytes that is more than current 128 bytes. In this case expand header flow is reached. The warning in skb_try_coalesce() caused by a wrong truesize was already fixed here: commit 158f323b9868 ("net: adjust skb->truesize in pskb_expand_head()"). Still, we prefer to totally avoid the expand header flow for performance reasons. Tested regular TCP_STREAM with iperf for 1 and 8 streams, no degradation was found. Fixes: 461017cb006a ("net/mlx5e: Support RX multi-packet WQE (Striding RQ)") Signed-off-by: Eugenia Emantayev Signed-off-by: Saeed Mahameed Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/mellanox/mlx5/core/en.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/ethernet/mellanox/mlx5/core/en.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h @@ -82,7 +82,7 @@ #define MLX5E_VALID_NUM_MTTS(num_mtts) (MLX5_MTT_OCTW(num_mtts) - 1 <= U16_MAX) #define MLX5_UMR_ALIGN (2048) -#define MLX5_MPWRQ_SMALL_PACKET_THRESHOLD (128) +#define MLX5_MPWRQ_SMALL_PACKET_THRESHOLD (256) #define MLX5E_PARAMS_DEFAULT_LRO_WQE_SZ (64 * 1024) #define MLX5E_DEFAULT_LRO_TIMEOUT 32