From patchwork Mon Jan 4 13:07:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Giuseppe CAVALLARO X-Patchwork-Id: 562373 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4894A14030D for ; Mon, 4 Jan 2016 23:54:44 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753474AbcADMyk (ORCPT ); Mon, 4 Jan 2016 07:54:40 -0500 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:44353 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753829AbcADMyf (ORCPT ); Mon, 4 Jan 2016 07:54:35 -0500 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx08-00178001.pphosted.com (8.14.5/8.14.5) with SMTP id u04CrFsJ022688 for ; Mon, 4 Jan 2016 13:54:33 +0100 Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx08-00178001.pphosted.com with ESMTP id 2034vyx79t-1 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Mon, 04 Jan 2016 13:54:33 +0100 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 21BCA34 for ; Mon, 4 Jan 2016 12:53:49 +0000 (GMT) Received: from Webmail-eu.st.com (Safex1hubcas21.st.com [10.75.90.44]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 533F250FC for ; Mon, 4 Jan 2016 12:54:31 +0000 (GMT) Received: from localhost (164.130.129.175) by Webmail-ga.st.com (10.75.90.48) with Microsoft SMTP Server (TLS) id 14.3.235.1; Mon, 4 Jan 2016 13:54:31 +0100 From: Giuseppe Cavallaro To: CC: , Giuseppe Cavallaro Subject: [PATCH (net-next.git) 17/18] stmmac: tune rx copy via threshold. Date: Mon, 4 Jan 2016 14:07:02 +0100 Message-ID: <1451912823-5245-18-git-send-email-peppe.cavallaro@st.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1451912823-5245-1-git-send-email-peppe.cavallaro@st.com> References: <1451912823-5245-1-git-send-email-peppe.cavallaro@st.com> MIME-Version: 1.0 X-Originating-IP: [164.130.129.175] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.15.21, 1.0.33, 0.0.0000 definitions=2016-01-04_07:2016-01-02, 2016-01-04, 1970-01-01 signatures=0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org There is a threshold now used to also limit the skb allocation when use zero-copy. This is to avoid that there are incoherence in the ring due to a failure on skb allocation under very aggressive testing and under low memory conditions. Signed-off-by: Giuseppe Cavallaro --- drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 + drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 26 +++++++++++++++++++- 2 files changed, 25 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h index c94ae65..9c62b86 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h @@ -77,6 +77,7 @@ struct stmmac_priv { unsigned int dma_rx_size; unsigned int dma_buf_sz; unsigned int rx_copybreak; + unsigned int rx_zeroc_thresh; u32 rx_riwt; int hwts_rx_en; dma_addr_t *rx_skbuff_dma; diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index b431046..71bda4e 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -201,6 +201,7 @@ static void print_pkt(unsigned char *buf, int len) /* minimum number of free TX descriptors required to wake up TX process */ #define STMMAC_TX_THRESH(x) (x->dma_tx_size/4) +#define STMMAC_RX_THRESH(x) (x->dma_rx_size / 4) static inline u32 stmmac_tx_avail(struct stmmac_priv *priv) { @@ -2173,6 +2174,14 @@ static void stmmac_rx_vlan(struct net_device *dev, struct sk_buff *skb) } +static inline int stmmac_rx_threshold_count(struct stmmac_priv *priv) +{ + if (priv->rx_zeroc_thresh < STMMAC_RX_THRESH(priv)) + return 0; + + return 1; +} + /** * stmmac_rx_refill - refill used skb preallocated buffers * @priv: driver private structure @@ -2198,8 +2207,15 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv) struct sk_buff *skb; skb = netdev_alloc_skb_ip_align(priv->dev, bfsize); - if (unlikely(!skb)) + if (unlikely(!skb)) { + /* so for a while no zero-copy! */ + priv->rx_zeroc_thresh = STMMAC_RX_THRESH(priv); + if (unlikely(net_ratelimit())) + dev_err(priv->device, + "fail to alloc skb entry %d\n", + entry); break; + } priv->rx_skbuff[entry] = skb; priv->rx_skbuff_dma[entry] = @@ -2215,9 +2231,13 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv) priv->hw->mode->refill_desc3(priv, p); + if (priv->rx_zeroc_thresh > 0) + priv->rx_zeroc_thresh--; + if (netif_msg_rx_status(priv)) pr_debug("\trefill entry #%d\n", entry); } + wmb(); priv->hw->desc->set_rx_owner(p); wmb(); @@ -2322,7 +2342,8 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit) frame_len, status); } - if (unlikely(frame_len < priv->rx_copybreak)) { + if (unlikely((frame_len < priv->rx_copybreak) || + stmmac_rx_threshold_count(priv))) { skb = netdev_alloc_skb_ip_align(priv->dev, frame_len); if (unlikely(!skb)) { @@ -2357,6 +2378,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit) } prefetch(skb->data - NET_IP_ALIGN); priv->rx_skbuff[entry] = NULL; + priv->rx_zeroc_thresh++; skb_put(skb, frame_len); dma_unmap_single(priv->device,