pasemi_mac: SKB unmap optimization
pasemi_mac: SKB unmap optimization Avoid touching skb_shinfo() in the unmap path, since it turns out to normally cause cache misses and delays. instead, save number of fragments in the TX_RING_INFO structures since that's all that's needed anyway. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
parent
28ae79f531
commit
7e9916e9dd
|
@ -253,11 +253,11 @@ static int get_skb_hdr(struct sk_buff *skb, void **iphdr,
|
|||
}
|
||||
|
||||
static int pasemi_mac_unmap_tx_skb(struct pasemi_mac *mac,
|
||||
const int nfrags,
|
||||
struct sk_buff *skb,
|
||||
const dma_addr_t *dmas)
|
||||
{
|
||||
int f;
|
||||
int nfrags = skb_shinfo(skb)->nr_frags;
|
||||
struct pci_dev *pdev = mac->dma_pdev;
|
||||
|
||||
pci_unmap_single(pdev, dmas[0], skb_headlen(skb), PCI_DMA_TODEVICE);
|
||||
|
@ -425,7 +425,7 @@ static void pasemi_mac_free_tx_resources(struct pasemi_mac *mac)
|
|||
unsigned int i, j;
|
||||
struct pasemi_mac_buffer *info;
|
||||
dma_addr_t dmas[MAX_SKB_FRAGS+1];
|
||||
int freed;
|
||||
int freed, nfrags;
|
||||
int start, limit;
|
||||
|
||||
start = txring->next_to_clean;
|
||||
|
@ -438,10 +438,12 @@ static void pasemi_mac_free_tx_resources(struct pasemi_mac *mac)
|
|||
for (i = start; i < limit; i += freed) {
|
||||
info = &txring->ring_info[(i+1) & (TX_RING_SIZE-1)];
|
||||
if (info->dma && info->skb) {
|
||||
for (j = 0; j <= skb_shinfo(info->skb)->nr_frags; j++)
|
||||
nfrags = skb_shinfo(info->skb)->nr_frags;
|
||||
for (j = 0; j <= nfrags; j++)
|
||||
dmas[j] = txring->ring_info[(i+1+j) &
|
||||
(TX_RING_SIZE-1)].dma;
|
||||
freed = pasemi_mac_unmap_tx_skb(mac, info->skb, dmas);
|
||||
freed = pasemi_mac_unmap_tx_skb(mac, nfrags,
|
||||
info->skb, dmas);
|
||||
} else
|
||||
freed = 2;
|
||||
}
|
||||
|
@ -749,6 +751,8 @@ static int pasemi_mac_clean_tx(struct pasemi_mac_txring *txring)
|
|||
unsigned long flags;
|
||||
struct sk_buff *skbs[TX_CLEAN_BATCHSIZE];
|
||||
dma_addr_t dmas[TX_CLEAN_BATCHSIZE][MAX_SKB_FRAGS+1];
|
||||
int nf[TX_CLEAN_BATCHSIZE];
|
||||
int nr_frags;
|
||||
|
||||
total_count = 0;
|
||||
batch_limit = TX_CLEAN_BATCHSIZE;
|
||||
|
@ -758,6 +762,8 @@ restart:
|
|||
start = txring->next_to_clean;
|
||||
ring_limit = txring->next_to_fill;
|
||||
|
||||
prefetch(&TX_DESC_INFO(txring, start+1).skb);
|
||||
|
||||
/* Compensate for when fill has wrapped but clean has not */
|
||||
if (start > ring_limit)
|
||||
ring_limit += TX_RING_SIZE;
|
||||
|
@ -771,6 +777,9 @@ restart:
|
|||
u64 mactx = TX_DESC(txring, i);
|
||||
struct sk_buff *skb;
|
||||
|
||||
skb = TX_DESC_INFO(txring, i+1).skb;
|
||||
nr_frags = TX_DESC_INFO(txring, i).dma;
|
||||
|
||||
if ((mactx & XCT_MACTX_E) ||
|
||||
(*chan->status & PAS_STATUS_ERROR))
|
||||
pasemi_mac_tx_error(mac, mactx);
|
||||
|
@ -779,21 +788,22 @@ restart:
|
|||
/* Not yet transmitted */
|
||||
break;
|
||||
|
||||
skb = TX_DESC_INFO(txring, i+1).skb;
|
||||
skbs[descr_count] = skb;
|
||||
|
||||
buf_count = 2 + skb_shinfo(skb)->nr_frags;
|
||||
for (j = 0; j <= skb_shinfo(skb)->nr_frags; j++)
|
||||
dmas[descr_count][j] = TX_DESC_INFO(txring, i+1+j).dma;
|
||||
|
||||
TX_DESC(txring, i) = 0;
|
||||
TX_DESC(txring, i+1) = 0;
|
||||
|
||||
buf_count = 2 + nr_frags;
|
||||
/* Since we always fill with an even number of entries, make
|
||||
* sure we skip any unused one at the end as well.
|
||||
*/
|
||||
if (buf_count & 1)
|
||||
buf_count++;
|
||||
|
||||
for (j = 0; j <= nr_frags; j++)
|
||||
dmas[descr_count][j] = TX_DESC_INFO(txring, i+1+j).dma;
|
||||
|
||||
skbs[descr_count] = skb;
|
||||
nf[descr_count] = nr_frags;
|
||||
|
||||
TX_DESC(txring, i) = 0;
|
||||
TX_DESC(txring, i+1) = 0;
|
||||
|
||||
descr_count++;
|
||||
}
|
||||
txring->next_to_clean = i & (TX_RING_SIZE-1);
|
||||
|
@ -802,7 +812,7 @@ restart:
|
|||
netif_wake_queue(mac->netdev);
|
||||
|
||||
for (i = 0; i < descr_count; i++)
|
||||
pasemi_mac_unmap_tx_skb(mac, skbs[i], dmas[i]);
|
||||
pasemi_mac_unmap_tx_skb(mac, nf[i], skbs[i], dmas[i]);
|
||||
|
||||
total_count += descr_count;
|
||||
|
||||
|
@ -1299,6 +1309,7 @@ static int pasemi_mac_start_tx(struct sk_buff *skb, struct net_device *dev)
|
|||
}
|
||||
|
||||
TX_DESC(txring, fill) = mactx;
|
||||
TX_DESC_INFO(txring, fill).dma = nfrags;
|
||||
fill++;
|
||||
TX_DESC_INFO(txring, fill).skb = skb;
|
||||
for (i = 0; i <= nfrags; i++) {
|
||||
|
|
Loading…
Reference in New Issue