From patchwork Thu Jun 16 22:02:27 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Scott J. Goldman" X-Patchwork-Id: 100735 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 A6225B6F6E for ; Fri, 17 Jun 2011 08:04:38 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161002Ab1FPWEc (ORCPT ); Thu, 16 Jun 2011 18:04:32 -0400 Received: from smtp-outbound-2.vmware.com ([65.115.85.73]:42941 "EHLO smtp-outbound-2.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161027Ab1FPWEb (ORCPT ); Thu, 16 Jun 2011 18:04:31 -0400 Received: from mailhost4.vmware.com (mailhost4.vmware.com [10.16.67.124]) by smtp-outbound-2.vmware.com (Postfix) with ESMTP id F01651A00A for ; Thu, 16 Jun 2011 15:04:30 -0700 (PDT) Received: from promd-1n-dhcp85.eng.vmware.com (scottjg-dev.eng.vmware.com [10.20.118.44]) by mailhost4.vmware.com (Postfix) with ESMTP id E30B7C9E57; Thu, 16 Jun 2011 15:04:30 -0700 (PDT) From: "Scott J. Goldman" To: netdev@vger.kernel.org, pv-drivers@vmware.com Cc: "Scott J. Goldman" Subject: [PATCH] vmxnet3: fix starving rx ring when alloc_skb fails Date: Thu, 16 Jun 2011 15:02:27 -0700 Message-Id: <1308261747-17702-1-git-send-email-scottjg@vmware.com> X-Mailer: git-send-email 1.7.4.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org if the rx ring is completely empty, then the device may never fire an rx interrupt. unfortunately, the rx interrupt is what triggers populating the rx ring with fresh buffers, so this will cause networking to lock up. this patch recycles the last skb that we were about to indicate up to the network stack (only if the rx ring is completely starved of skbs) so the ring will never be completely empty. If we fail to allocate a secondary page buffer, we just indicate a 0 length buffer to the device. Signed-off-by: Scott J. Goldman Signed-off-by: Bhavesh Davda --- drivers/net/vmxnet3/vmxnet3_drv.c | 98 +++++++++++++++++++++++++----------- drivers/net/vmxnet3/vmxnet3_int.h | 5 +- 2 files changed, 70 insertions(+), 33 deletions(-) diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c index 33097ec..cfa9ff7 100644 --- a/drivers/net/vmxnet3/vmxnet3_drv.c +++ b/drivers/net/vmxnet3/vmxnet3_drv.c @@ -558,6 +558,17 @@ vmxnet3_tq_cleanup_all(struct vmxnet3_adapter *adapter) vmxnet3_tq_cleanup(&adapter->tx_queue[i], adapter); } +static bool +vmxnet3_rq_empty(const struct vmxnet3_rx_queue *rq, u32 ring_idx) +{ + const struct vmxnet3_cmd_ring *ring = &rq->rx_ring[ring_idx]; + u32 i = ring->next2comp; + while (rq->buf_info[ring_idx][i].buf_type != VMXNET3_RX_BUF_SKB) + VMXNET3_INC_RING_IDX_ONLY(i, ring->size); + + return (i == ring->next2fill); +} + /* * starting from ring->next2fill, allocate rx buffers for the given ring * of the rx queue and update the rx desc. stop after @num_to_alloc buffers @@ -571,9 +582,12 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx, int num_allocated = 0; struct vmxnet3_rx_buf_info *rbi_base = rq->buf_info[ring_idx]; struct vmxnet3_cmd_ring *ring = &rq->rx_ring[ring_idx]; + struct vmxnet3_rx_ctx *ctx = &rq->rx_ctx; + bool alloc_skb_failed = false; u32 val; + u32 len; - while (num_allocated < num_to_alloc) { + while (num_allocated < num_to_alloc && !alloc_skb_failed) { struct vmxnet3_rx_buf_info *rbi; union Vmxnet3_GenericDesc *gd; @@ -586,7 +600,27 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx, NET_IP_ALIGN); if (unlikely(rbi->skb == NULL)) { rq->stats.rx_buf_alloc_failure++; - break; + alloc_skb_failed = true; + /* + * if allocation failed and ring is + * empty, we recycle the last skb we + * rx'ed so that we don't starve the + * rx ring + */ + if (ctx->skb && + vmxnet3_rq_empty(rq, ring_idx)) { + rbi->skb = ctx->skb; + ctx->skb = NULL; + skb_recycle_check(rbi->skb, + rbi->len + + NET_IP_ALIGN); + /* + * free any frags chained to + * the skb + */ + __pskb_trim(rbi->skb, 0); + } else + break; } rbi->skb->dev = adapter->netdev; @@ -594,8 +628,10 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx, rbi->dma_addr = pci_map_single(adapter->pdev, rbi->skb->data, rbi->len, PCI_DMA_FROMDEVICE); + len = rbi->len; } else { /* rx buffer skipped by the device */ + len = rbi->len; } val = VMXNET3_RXD_BTYPE_HEAD << VMXNET3_RXD_BTYPE_SHIFT; } else { @@ -606,13 +642,18 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx, rbi->page = alloc_page(GFP_ATOMIC); if (unlikely(rbi->page == NULL)) { rq->stats.rx_buf_alloc_failure++; - break; + len = 0; + } else { + rbi->dma_addr = pci_map_page( + adapter->pdev, + rbi->page, 0, + PAGE_SIZE, + PCI_DMA_FROMDEVICE); + len = rbi->len; } - rbi->dma_addr = pci_map_page(adapter->pdev, - rbi->page, 0, PAGE_SIZE, - PCI_DMA_FROMDEVICE); } else { /* rx buffers skipped by the device */ + len = rbi->len; } val = VMXNET3_RXD_BTYPE_BODY << VMXNET3_RXD_BTYPE_SHIFT; } @@ -620,7 +661,7 @@ vmxnet3_rq_alloc_rx_buf(struct vmxnet3_rx_queue *rq, u32 ring_idx, BUG_ON(rbi->dma_addr == 0); gd->rxd.addr = cpu_to_le64(rbi->dma_addr); gd->dword[2] = cpu_to_le32((ring->gen << VMXNET3_RXD_GEN_SHIFT) - | val | rbi->len); + | val | len); num_allocated++; vmxnet3_cmd_ring_adv_next2fill(ring); @@ -1148,7 +1189,6 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, &rxComp); while (rcd->gen == rq->comp_ring.gen) { struct vmxnet3_rx_buf_info *rbi; - struct sk_buff *skb; int num_to_alloc; struct Vmxnet3_RxDesc *rxd; u32 idx, ring_idx; @@ -1168,7 +1208,7 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, rbi = rq->buf_info[ring_idx] + idx; BUG_ON(rxd->addr != rbi->dma_addr || - rxd->len != rbi->len); + (rxd->len != rbi->len && rbi->len != 0)); if (unlikely(rcd->eop && rcd->err)) { vmxnet3_rx_error(rq, rcd, ctx, adapter); @@ -1198,8 +1238,7 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, PCI_DMA_FROMDEVICE); skb_put(ctx->skb, rcd->len); - } else { - BUG_ON(ctx->skb == NULL); + } else if (ctx->skb) { /* non SOP buffer must be type 1 in most cases */ if (rbi->buf_type == VMXNET3_RX_BUF_PAGE) { BUG_ON(rxd->btype != VMXNET3_RXD_BTYPE_BODY); @@ -1222,25 +1261,6 @@ vmxnet3_rq_rx_complete(struct vmxnet3_rx_queue *rq, } } - skb = ctx->skb; - if (rcd->eop) { - skb->len += skb->data_len; - skb->truesize += skb->data_len; - - vmxnet3_rx_csum(adapter, skb, - (union Vmxnet3_GenericDesc *)rcd); - skb->protocol = eth_type_trans(skb, adapter->netdev); - - if (unlikely(adapter->vlan_grp && rcd->ts)) { - vlan_hwaccel_receive_skb(skb, - adapter->vlan_grp, rcd->tci); - } else { - netif_receive_skb(skb); - } - - ctx->skb = NULL; - } - rcd_done: /* device may skip some rx descs */ rq->rx_ring[ring_idx].next2comp = idx; @@ -1264,6 +1284,24 @@ rcd_done: } } + if (rcd->eop && ctx->skb) { + ctx->skb->len += ctx->skb->data_len; + ctx->skb->truesize += ctx->skb->data_len; + + vmxnet3_rx_csum(adapter, ctx->skb, + (union Vmxnet3_GenericDesc *)rcd); + ctx->skb->protocol = eth_type_trans(ctx->skb, + adapter->netdev); + if (unlikely(adapter->vlan_grp && rcd->ts)) { + vlan_hwaccel_receive_skb(ctx->skb, + adapter->vlan_grp, + rcd->tci); + } else { + netif_receive_skb(ctx->skb); + } + ctx->skb = NULL; + } + vmxnet3_comp_ring_adv_next2proc(&rq->comp_ring); vmxnet3_getRxComp(rcd, &rq->comp_ring.base[rq->comp_ring.next2proc].rcd, &rxComp); diff --git a/drivers/net/vmxnet3/vmxnet3_int.h b/drivers/net/vmxnet3/vmxnet3_int.h index 0e567c24..cb13ed7 100644 --- a/drivers/net/vmxnet3/vmxnet3_int.h +++ b/drivers/net/vmxnet3/vmxnet3_int.h @@ -68,10 +68,10 @@ /* * Version numbers */ -#define VMXNET3_DRIVER_VERSION_STRING "1.1.9.0-k" +#define VMXNET3_DRIVER_VERSION_STRING "1.1.10.0-k" /* a 32-bit int, each byte encode a verion number in VMXNET3_DRIVER_VERSION */ -#define VMXNET3_DRIVER_VERSION_NUM 0x01010900 +#define VMXNET3_DRIVER_VERSION_NUM 0x01010A00 #if defined(CONFIG_PCI_MSI) /* RSS only makes sense if MSI-X is supported. */ @@ -255,7 +255,6 @@ struct vmxnet3_rx_buf_info { struct vmxnet3_rx_ctx { struct sk_buff *skb; - u32 sop_idx; }; struct vmxnet3_rq_driver_stats {