Denis Vlasenko <vda@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> :
[...]
> Sorry Jeff your patch does not fix my problem.
> I also verified that it happens this way:
> (1) rx skb is processed and freed
> (2) allocation failure for new skb
> (3) next rx intr occurs, cur_rx->skbuff still == NULL
> (4) oops
Your previous analysis made sense: the logic responsible for low memory
handling is broken in several ways.
Patch against2.6.5-rc2-mm3 below, without warranty
--- drivers/net/fealnx.c 2004-03-28 00:44:27.000000000 +0100
+++ drivers/net/fealnx.c 2004-03-28 00:52:46.000000000 +0100
@@ -1134,15 +1134,17 @@ static void allocate_rx_buffers(struct n
struct sk_buff *skb;
skb = dev_alloc_skb(np->rx_buf_sz);
- np->lack_rxbuf->skbuff = skb;
-
if (skb == NULL)
break; /* Better luck next round. */
+ while (np->lack_rxbuf->skbuff)
+ np->lack_rxbuf = np->lack_rxbuf->next_desc_logical;
+ np->lack_rxbuf->skbuff = skb;
+
skb->dev = dev; /* Mark as being used by this device. */
np->lack_rxbuf->buffer = pci_map_single(np->pci_dev, skb->tail,
np->rx_buf_sz, PCI_DMA_FROMDEVICE);
- np->lack_rxbuf = np->lack_rxbuf->next_desc_logical;
+ np->lack_rxbuf->status = RXOWN;
++np->really_rx_count;
}
}
@@ -1380,33 +1382,22 @@ static int start_tx(struct sk_buff *skb,
return 0;
}
-
-void free_one_rx_descriptor(struct netdev_private *np)
-{
- if (np->really_rx_count == RX_RING_SIZE)
- np->cur_rx->status = RXOWN;
- else {
- np->lack_rxbuf->skbuff = np->cur_rx->skbuff;
- np->lack_rxbuf->buffer = np->cur_rx->buffer;
- np->lack_rxbuf->status = RXOWN;
- ++np->really_rx_count;
- np->lack_rxbuf = np->lack_rxbuf->next_desc_logical;
- }
- np->cur_rx = np->cur_rx->next_desc_logical;
-}
-
-
void reset_rx_descriptors(struct net_device *dev)
{
struct netdev_private *np = dev->priv;
+ struct fealnx_desc *cur = np->cur_rx;
+ int i;
stop_nic_rx(dev->base_addr, np->crvalue);
- while (!(np->cur_rx->status & RXOWN))
- free_one_rx_descriptor(np);
-
allocate_rx_buffers(dev);
+ for (i = 0; i < RX_RING_SIZE; i++) {
+ if (cur->skbuff)
+ cur->status = RXOWN;
+ cur = cur->next_desc_logical;
+ }
+
writel(np->rx_ring_dma + (np->cur_rx - np->rx_ring),
dev->base_addr + RXLBA);
writel(np->crvalue, dev->base_addr + TCRRCR);
@@ -1576,7 +1567,7 @@ static int netdev_rx(struct net_device *
struct netdev_private *np = dev->priv;
/* If EOP is set on the next entry, it's a new packet. Send it up. */
- while (!(np->cur_rx->status & RXOWN)) {
+ while (!(np->cur_rx->status & RXOWN) && np->cur_rx->skbuff) {
s32 rx_status = np->cur_rx->status;
if (np->really_rx_count == 0)
@@ -1628,8 +1619,15 @@ static int netdev_rx(struct net_device *
np->stats.rx_length_errors++;
/* free all rx descriptors related this
long pkt */
- for (i = 0; i < desno; ++i)
- free_one_rx_descriptor(np);
+ for (i = 0; i < desno; ++i) {
+ if (!np->cur_rx->skbuff) {
+ printk(KERN_DEBUG
+ "%s: I'm
scared\n", dev->name);
+ break;
+ }
+ np->cur_rx->status = RXOWN;
+ np->cur_rx =
np->cur_rx->next_desc_logical;
+ }
continue;
} else { /* something error, need to
reset this chip */
reset_rx_descriptors(dev);
@@ -1679,8 +1677,6 @@ static int netdev_rx(struct net_device *
PCI_DMA_FROMDEVICE);
skb_put(skb = np->cur_rx->skbuff, pkt_len);
np->cur_rx->skbuff = NULL;
- if (np->really_rx_count == RX_RING_SIZE)
- np->lack_rxbuf = np->cur_rx;
--np->really_rx_count;
}
skb->protocol = eth_type_trans(skb, dev);
@@ -1689,25 +1685,7 @@ static int netdev_rx(struct net_device *
np->stats.rx_packets++;
np->stats.rx_bytes += pkt_len;
}
-
- if (np->cur_rx->skbuff == NULL) {
- struct sk_buff *skb;
-
- skb = dev_alloc_skb(np->rx_buf_sz);
-
- if (skb != NULL) {
- skb->dev = dev; /* Mark as being used by this
device. */
- np->cur_rx->buffer = pci_map_single(np->pci_dev,
- skb->tail,
-
np->rx_buf_sz,
-
PCI_DMA_FROMDEVICE);
- np->cur_rx->skbuff = skb;
- ++np->really_rx_count;
- }
- }
-
- if (np->cur_rx->skbuff != NULL)
- free_one_rx_descriptor(np);
+ np->cur_rx = np->cur_rx->next_desc_logical;
} /* end of while loop */
/* allocate skb for rx buffers */
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