mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-13 23:24:05 +08:00
c9e6bc644e
This adds a new include file (include/net/gro_cells.h), to bring GRO (Generic Receive Offload) capability to tunnels, in a modular way. Because tunnels receive path is lockless, and GRO adds a serialization using a napi_struct, I chose to add an array of up to DEFAULT_MAX_NUM_RSS_QUEUES cells, so that multi queue devices wont be slowed down because of GRO layer. skb_get_rx_queue() is used as selector. In the future, we might add optional fanout capabilities, using rxhash for example. With help from Ben Hutchings who reminded me netif_get_num_default_rss_queues() function. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
104 lines
2.3 KiB
C
104 lines
2.3 KiB
C
#ifndef _NET_GRO_CELLS_H
|
|
#define _NET_GRO_CELLS_H
|
|
|
|
#include <linux/skbuff.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/netdevice.h>
|
|
|
|
struct gro_cell {
|
|
struct sk_buff_head napi_skbs;
|
|
struct napi_struct napi;
|
|
} ____cacheline_aligned_in_smp;
|
|
|
|
struct gro_cells {
|
|
unsigned int gro_cells_mask;
|
|
struct gro_cell *cells;
|
|
};
|
|
|
|
static inline void gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
|
|
{
|
|
unsigned long flags;
|
|
struct gro_cell *cell = gcells->cells;
|
|
struct net_device *dev = skb->dev;
|
|
|
|
if (!cell || skb_cloned(skb) || !(dev->features & NETIF_F_GRO)) {
|
|
netif_rx(skb);
|
|
return;
|
|
}
|
|
|
|
if (skb_rx_queue_recorded(skb))
|
|
cell += skb_get_rx_queue(skb) & gcells->gro_cells_mask;
|
|
|
|
if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
|
|
atomic_long_inc(&dev->rx_dropped);
|
|
kfree_skb(skb);
|
|
return;
|
|
}
|
|
|
|
spin_lock_irqsave(&cell->napi_skbs.lock, flags);
|
|
|
|
__skb_queue_tail(&cell->napi_skbs, skb);
|
|
if (skb_queue_len(&cell->napi_skbs) == 1)
|
|
napi_schedule(&cell->napi);
|
|
|
|
spin_unlock_irqrestore(&cell->napi_skbs.lock, flags);
|
|
}
|
|
|
|
static inline int gro_cell_poll(struct napi_struct *napi, int budget)
|
|
{
|
|
struct gro_cell *cell = container_of(napi, struct gro_cell, napi);
|
|
struct sk_buff *skb;
|
|
int work_done = 0;
|
|
|
|
while (work_done < budget) {
|
|
skb = skb_dequeue(&cell->napi_skbs);
|
|
if (!skb)
|
|
break;
|
|
|
|
napi_gro_receive(napi, skb);
|
|
work_done++;
|
|
}
|
|
|
|
if (work_done < budget)
|
|
napi_complete(napi);
|
|
return work_done;
|
|
}
|
|
|
|
static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *dev)
|
|
{
|
|
int i;
|
|
|
|
gcells->gro_cells_mask = roundup_pow_of_two(netif_get_num_default_rss_queues()) - 1;
|
|
gcells->cells = kcalloc(sizeof(struct gro_cell),
|
|
gcells->gro_cells_mask + 1,
|
|
GFP_KERNEL);
|
|
if (!gcells->cells)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; i <= gcells->gro_cells_mask; i++) {
|
|
struct gro_cell *cell = gcells->cells + i;
|
|
|
|
skb_queue_head_init(&cell->napi_skbs);
|
|
netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
|
|
napi_enable(&cell->napi);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static inline void gro_cells_destroy(struct gro_cells *gcells)
|
|
{
|
|
struct gro_cell *cell = gcells->cells;
|
|
int i;
|
|
|
|
if (!cell)
|
|
return;
|
|
for (i = 0; i <= gcells->gro_cells_mask; i++,cell++) {
|
|
netif_napi_del(&cell->napi);
|
|
skb_queue_purge(&cell->napi_skbs);
|
|
}
|
|
kfree(gcells->cells);
|
|
gcells->cells = NULL;
|
|
}
|
|
|
|
#endif
|