From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:39640 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727001AbfKNKTt (ORCPT ); Thu, 14 Nov 2019 05:19:49 -0500 Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id xAEAIfWh112668 for ; Thu, 14 Nov 2019 05:19:48 -0500 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2w91m7ejv5-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 14 Nov 2019 05:19:46 -0500 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 14 Nov 2019 10:19:34 -0000 From: Julian Wiedmann Subject: [PATCH net-next 04/11] s390/qeth: handle skb allocation error gracefully Date: Thu, 14 Nov 2019 11:19:17 +0100 In-Reply-To: <20191114101924.29558-1-jwi@linux.ibm.com> References: <20191114101924.29558-1-jwi@linux.ibm.com> Message-Id: <20191114101924.29558-5-jwi@linux.ibm.com> Sender: linux-s390-owner@vger.kernel.org List-ID: To: David Miller Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org, Heiko Carstens , Stefan Raspl , Ursula Braun , Julian Wiedmann When current code fails to allocate an skb in the RX path, it drops the whole RX buffer. Considering the large number of packets that a single RX buffer might contain, this is quite drastic. Skip over the packet instead, and try to extract the next packet from the RX buffer. Signed-off-by: Julian Wiedmann --- drivers/s390/net/qeth_core_main.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index 467a9173058c..08185f76a727 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -5065,12 +5065,12 @@ struct sk_buff *qeth_core_get_next_skb(struct qeth_card *card, struct qdio_buffer_element *element = *__element; struct qdio_buffer *buffer = qethbuffer->buffer; int offset = *__offset; + bool use_rx_sg = false; + unsigned int headroom; struct sk_buff *skb; int skb_len = 0; void *data_ptr; int data_len; - int headroom = 0; - int use_rx_sg = 0; next_packet: /* qeth_hdr must not cross element boundaries */ @@ -5086,6 +5086,7 @@ struct sk_buff *qeth_core_get_next_skb(struct qeth_card *card, switch ((*hdr)->hdr.l2.id) { case QETH_HEADER_TYPE_LAYER2: skb_len = (*hdr)->hdr.l2.pkt_length; + headroom = 0; break; case QETH_HEADER_TYPE_LAYER3: skb_len = (*hdr)->hdr.l3.length; @@ -5120,11 +5121,10 @@ struct sk_buff *qeth_core_get_next_skb(struct qeth_card *card, if (!skb_len) return NULL; - if (((skb_len >= card->options.rx_sg_cb) && - !IS_OSN(card) && - (!atomic_read(&card->force_alloc_skb))) || - (card->options.cq == QETH_CQ_ENABLED)) - use_rx_sg = 1; + use_rx_sg = (card->options.cq == QETH_CQ_ENABLED) || + ((skb_len >= card->options.rx_sg_cb) && + !atomic_read(&card->force_alloc_skb) && + !IS_OSN(card)); if (use_rx_sg && qethbuffer->rx_skb) { /* QETH_CQ_ENABLED only: */ @@ -5135,9 +5135,10 @@ struct sk_buff *qeth_core_get_next_skb(struct qeth_card *card, skb = napi_alloc_skb(&card->napi, linear + headroom); } + if (!skb) - goto no_mem; - if (headroom) + QETH_CARD_STAT_INC(card, rx_dropped_nomem); + else if (headroom) skb_reserve(skb, headroom); walk_packet: @@ -5184,12 +5185,6 @@ struct sk_buff *qeth_core_get_next_skb(struct qeth_card *card, skb_shinfo(skb)->nr_frags); } return skb; -no_mem: - if (net_ratelimit()) { - QETH_CARD_TEXT(card, 2, "noskbmem"); - } - QETH_CARD_STAT_INC(card, rx_dropped_nomem); - return NULL; } EXPORT_SYMBOL_GPL(qeth_core_get_next_skb); -- 2.17.1