From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Falcon Subject: [PATCH 1/2 net] ibmvnic: Fix overflowing firmware/hardware TX queue Date: Sun, 5 Mar 2017 12:10:23 -0600 Message-ID: <1488737424-17067-1-git-send-email-tlfalcon@linux.vnet.ibm.com> Cc: jallen@linux.vnet.ibm.com, nfont@linux.vnic.ibm.com, wvoigt@us.ibm.com To: netdev@vger.kernel.org Return-path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:40207 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751007AbdCEUdD (ORCPT ); Sun, 5 Mar 2017 15:33:03 -0500 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v25I8Zgu041819 for ; Sun, 5 Mar 2017 13:10:32 -0500 Received: from e31.co.us.ibm.com (e31.co.us.ibm.com [32.97.110.149]) by mx0b-001b2d01.pphosted.com with ESMTP id 28yu2hqngf-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Sun, 05 Mar 2017 13:10:32 -0500 Received: from localhost by e31.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 5 Mar 2017 11:10:32 -0700 Received: from b03cxnp08026.gho.boulder.ibm.com (b03cxnp08026.gho.boulder.ibm.com [9.17.130.18]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id 0F4ED19D803F for ; Sun, 5 Mar 2017 11:09:39 -0700 (MST) Sender: netdev-owner@vger.kernel.org List-ID: Use a counter to track the number of outstanding transmissions sent that have not received completions. If the counter reaches the maximum number of queue entries, stop transmissions on that queue. As we receive more completions from firmware, wake the queue once the counter reaches an acceptable level. This patch prevents hardware/firmware TX queue from filling up and and generating errors. Since incorporating this fix, internal testing has reported that these firmware errors have stopped. Signed-off-by: Thomas Falcon --- drivers/net/ethernet/ibm/ibmvnic.c | 27 ++++++++++++++++++++++++++- drivers/net/ethernet/ibm/ibmvnic.h | 1 + 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 9198e6b..0e87b83 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -705,6 +705,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) u8 *hdrs = (u8 *)&adapter->tx_rx_desc_req; struct device *dev = &adapter->vdev->dev; struct ibmvnic_tx_buff *tx_buff = NULL; + struct ibmvnic_sub_crq_queue *tx_scrq; struct ibmvnic_tx_pool *tx_pool; unsigned int tx_send_failed = 0; unsigned int tx_map_failed = 0; @@ -724,6 +725,7 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) int ret = 0; tx_pool = &adapter->tx_pool[queue_num]; + tx_scrq = adapter->tx_scrq[queue_num]; txq = netdev_get_tx_queue(netdev, skb_get_queue_mapping(skb)); handle_array = (u64 *)((u8 *)(adapter->login_rsp_buf) + be32_to_cpu(adapter->login_rsp_buf-> @@ -826,6 +828,14 @@ static int ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) ret = NETDEV_TX_BUSY; goto out; } + + atomic_inc(&tx_scrq->used); + + if (atomic_read(&tx_scrq->used) >= adapter->req_tx_entries_per_subcrq) { + netdev_info(netdev, "Stopping queue %d\n", queue_num); + netif_stop_subqueue(netdev, queue_num); + } + tx_packets++; tx_bytes += skb->len; txq->trans_start = jiffies; @@ -1213,6 +1223,7 @@ static struct ibmvnic_sub_crq_queue *init_sub_crq_queue(struct ibmvnic_adapter scrq->adapter = adapter; scrq->size = 4 * PAGE_SIZE / sizeof(*scrq->msgs); scrq->cur = 0; + atomic_set(&scrq->used, 0); scrq->rx_skb_top = NULL; spin_lock_init(&scrq->lock); @@ -1355,8 +1366,22 @@ static int ibmvnic_complete_tx(struct ibmvnic_adapter *adapter, DMA_TO_DEVICE); } - if (txbuff->last_frag) + if (txbuff->last_frag) { + atomic_dec(&scrq->used); + + if (atomic_read(&scrq->used) <= + (adapter->req_tx_entries_per_subcrq / 2) && + netif_subqueue_stopped(adapter->netdev, + txbuff->skb)) { + netif_wake_subqueue(adapter->netdev, + scrq->pool_index); + netdev_dbg(adapter->netdev, + "Started queue %d\n", + scrq->pool_index); + } + dev_kfree_skb_any(txbuff->skb); + } adapter->tx_pool[pool].free_map[adapter->tx_pool[pool]. producer_index] = index; diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h index 422824f..1993b42 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.h +++ b/drivers/net/ethernet/ibm/ibmvnic.h @@ -863,6 +863,7 @@ struct ibmvnic_sub_crq_queue { spinlock_t lock; struct sk_buff *rx_skb_top; struct ibmvnic_adapter *adapter; + atomic_t used; }; struct ibmvnic_long_term_buff { -- 1.8.3.1