mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 21:54:06 +08:00
tg3: provide frags as skb head
This patch converts tg3 driver, one of our reference drivers, to use new build_skb() api in frag mode. Instead of using kmalloc() to allocate the memory block that will be used by build_skb() as skb->head, we use a page fragment. This is a followup of patch "net: allow skb->head to be a page fragment" This allows GRO, TCP coalescing, and splice() to be more efficient. Incidentally, this also removes SLUB slow path contention in kfree() Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Maciej Żenczykowski <maze@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Matt Carlson <mcarlson@broadcom.com> Cc: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
parent
d3836f21b0
commit
8d4057a938
@ -195,6 +195,15 @@ static inline void _tg3_flag_clear(enum TG3_FLAGS flag, unsigned long *bits)
|
||||
#define TG3_RX_OFFSET(tp) (NET_SKB_PAD)
|
||||
#endif
|
||||
|
||||
/* This driver uses the new build_skb() API providing a frag as skb->head
|
||||
* This strategy permits better GRO aggregation, better TCP coalescing, and
|
||||
* better splice() implementation (avoids a copy from head to a page), at
|
||||
* minimal memory cost.
|
||||
* In this 2048 bytes block, we have enough room to store the MTU=1500 frame
|
||||
* and the struct skb_shared_info.
|
||||
*/
|
||||
#define TG3_FRAGSIZE 2048
|
||||
|
||||
/* minimum number of free TX descriptors required to wake up TX process */
|
||||
#define TG3_TX_WAKEUP_THRESH(tnapi) ((tnapi)->tx_pending / 4)
|
||||
#define TG3_TX_BD_DMA_MAX_2K 2048
|
||||
@ -5617,17 +5626,48 @@ static void tg3_tx(struct tg3_napi *tnapi)
|
||||
}
|
||||
}
|
||||
|
||||
static void *tg3_frag_alloc(struct tg3_rx_prodring_set *tpr)
|
||||
{
|
||||
void *data;
|
||||
|
||||
if (tpr->rx_page_size < TG3_FRAGSIZE) {
|
||||
struct page *page = alloc_page(GFP_ATOMIC);
|
||||
|
||||
if (!page)
|
||||
return NULL;
|
||||
atomic_add((PAGE_SIZE / TG3_FRAGSIZE) - 1, &page->_count);
|
||||
tpr->rx_page_addr = page_address(page);
|
||||
tpr->rx_page_size = PAGE_SIZE;
|
||||
}
|
||||
data = tpr->rx_page_addr;
|
||||
tpr->rx_page_addr += TG3_FRAGSIZE;
|
||||
tpr->rx_page_size -= TG3_FRAGSIZE;
|
||||
return data;
|
||||
}
|
||||
|
||||
static void tg3_frag_free(bool is_frag, void *data)
|
||||
{
|
||||
if (is_frag)
|
||||
put_page(virt_to_head_page(data));
|
||||
else
|
||||
kfree(data);
|
||||
}
|
||||
|
||||
static void tg3_rx_data_free(struct tg3 *tp, struct ring_info *ri, u32 map_sz)
|
||||
{
|
||||
unsigned int skb_size = SKB_DATA_ALIGN(map_sz + TG3_RX_OFFSET(tp)) +
|
||||
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
|
||||
|
||||
if (!ri->data)
|
||||
return;
|
||||
|
||||
pci_unmap_single(tp->pdev, dma_unmap_addr(ri, mapping),
|
||||
map_sz, PCI_DMA_FROMDEVICE);
|
||||
kfree(ri->data);
|
||||
tg3_frag_free(skb_size <= TG3_FRAGSIZE, ri->data);
|
||||
ri->data = NULL;
|
||||
}
|
||||
|
||||
|
||||
/* Returns size of skb allocated or < 0 on error.
|
||||
*
|
||||
* We only need to fill in the address because the other members
|
||||
@ -5640,7 +5680,8 @@ static void tg3_rx_data_free(struct tg3 *tp, struct ring_info *ri, u32 map_sz)
|
||||
* (to fetch the error flags, vlan tag, checksum, and opaque cookie).
|
||||
*/
|
||||
static int tg3_alloc_rx_data(struct tg3 *tp, struct tg3_rx_prodring_set *tpr,
|
||||
u32 opaque_key, u32 dest_idx_unmasked)
|
||||
u32 opaque_key, u32 dest_idx_unmasked,
|
||||
unsigned int *frag_size)
|
||||
{
|
||||
struct tg3_rx_buffer_desc *desc;
|
||||
struct ring_info *map;
|
||||
@ -5675,7 +5716,13 @@ static int tg3_alloc_rx_data(struct tg3 *tp, struct tg3_rx_prodring_set *tpr,
|
||||
*/
|
||||
skb_size = SKB_DATA_ALIGN(data_size + TG3_RX_OFFSET(tp)) +
|
||||
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
|
||||
data = kmalloc(skb_size, GFP_ATOMIC);
|
||||
if (skb_size <= TG3_FRAGSIZE) {
|
||||
data = tg3_frag_alloc(tpr);
|
||||
*frag_size = TG3_FRAGSIZE;
|
||||
} else {
|
||||
data = kmalloc(skb_size, GFP_ATOMIC);
|
||||
*frag_size = 0;
|
||||
}
|
||||
if (!data)
|
||||
return -ENOMEM;
|
||||
|
||||
@ -5683,8 +5730,8 @@ static int tg3_alloc_rx_data(struct tg3 *tp, struct tg3_rx_prodring_set *tpr,
|
||||
data + TG3_RX_OFFSET(tp),
|
||||
data_size,
|
||||
PCI_DMA_FROMDEVICE);
|
||||
if (pci_dma_mapping_error(tp->pdev, mapping)) {
|
||||
kfree(data);
|
||||
if (unlikely(pci_dma_mapping_error(tp->pdev, mapping))) {
|
||||
tg3_frag_free(skb_size <= TG3_FRAGSIZE, data);
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
@ -5835,18 +5882,19 @@ static int tg3_rx(struct tg3_napi *tnapi, int budget)
|
||||
|
||||
if (len > TG3_RX_COPY_THRESH(tp)) {
|
||||
int skb_size;
|
||||
unsigned int frag_size;
|
||||
|
||||
skb_size = tg3_alloc_rx_data(tp, tpr, opaque_key,
|
||||
*post_ptr);
|
||||
*post_ptr, &frag_size);
|
||||
if (skb_size < 0)
|
||||
goto drop_it;
|
||||
|
||||
pci_unmap_single(tp->pdev, dma_addr, skb_size,
|
||||
PCI_DMA_FROMDEVICE);
|
||||
|
||||
skb = build_skb(data, 0);
|
||||
skb = build_skb(data, frag_size);
|
||||
if (!skb) {
|
||||
kfree(data);
|
||||
tg3_frag_free(frag_size != 0, data);
|
||||
goto drop_it_no_recycle;
|
||||
}
|
||||
skb_reserve(skb, TG3_RX_OFFSET(tp));
|
||||
@ -7279,7 +7327,10 @@ static int tg3_rx_prodring_alloc(struct tg3 *tp,
|
||||
|
||||
/* Now allocate fresh SKBs for each rx ring. */
|
||||
for (i = 0; i < tp->rx_pending; i++) {
|
||||
if (tg3_alloc_rx_data(tp, tpr, RXD_OPAQUE_RING_STD, i) < 0) {
|
||||
unsigned int frag_size;
|
||||
|
||||
if (tg3_alloc_rx_data(tp, tpr, RXD_OPAQUE_RING_STD, i,
|
||||
&frag_size) < 0) {
|
||||
netdev_warn(tp->dev,
|
||||
"Using a smaller RX standard ring. Only "
|
||||
"%d out of %d buffers were allocated "
|
||||
@ -7311,7 +7362,10 @@ static int tg3_rx_prodring_alloc(struct tg3 *tp,
|
||||
}
|
||||
|
||||
for (i = 0; i < tp->rx_jumbo_pending; i++) {
|
||||
if (tg3_alloc_rx_data(tp, tpr, RXD_OPAQUE_RING_JUMBO, i) < 0) {
|
||||
unsigned int frag_size;
|
||||
|
||||
if (tg3_alloc_rx_data(tp, tpr, RXD_OPAQUE_RING_JUMBO, i,
|
||||
&frag_size) < 0) {
|
||||
netdev_warn(tp->dev,
|
||||
"Using a smaller RX jumbo ring. Only %d "
|
||||
"out of %d buffers were allocated "
|
||||
|
@ -2815,6 +2815,8 @@ struct tg3_rx_prodring_set {
|
||||
struct ring_info *rx_jmb_buffers;
|
||||
dma_addr_t rx_std_mapping;
|
||||
dma_addr_t rx_jmb_mapping;
|
||||
void *rx_page_addr;
|
||||
unsigned int rx_page_size;
|
||||
};
|
||||
|
||||
#define TG3_IRQ_MAX_VECS_RSS 5
|
||||
|
Loading…
Reference in New Issue
Block a user