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authorMartin KaFai Lau <kafai@fb.com>2015-01-16 10:11:00 -0800
committerDavid S. Miller <davem@davemloft.net>2015-01-18 01:56:32 -0500
commit88340160f3ad22401b00f4efcee44f7ec4769b19 (patch)
treedebe361cc6501cc3584f70015e648b7d51cc2456 /include/net/gro_cells.h
parentf2bbca513c80081245ce2cb39f314ec37703afb3 (diff)
ip_tunnel: Create percpu gro_cell
In the ipip tunnel, the skb->queue_mapping is lost in ipip_rcv(). All skb will be queued to the same cell->napi_skbs. The gro_cell_poll is pinned to one core under load. In production traffic, we also see severe rx_dropped in the tunl iface and it is probably due to this limit: skb_queue_len(&cell->napi_skbs) > netdev_max_backlog. This patch is trying to alloc_percpu(struct gro_cell) and schedule gro_cell_poll to process the skb in the same core. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/gro_cells.h')
-rw-r--r--include/net/gro_cells.h29
1 files changed, 12 insertions, 17 deletions
diff --git a/include/net/gro_cells.h b/include/net/gro_cells.h
index 734d9b5f577a..0f712c0bc0bf 100644
--- a/include/net/gro_cells.h
+++ b/include/net/gro_cells.h
@@ -8,25 +8,23 @@
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;
+ struct gro_cell __percpu *cells;
};
static inline void gro_cells_receive(struct gro_cells *gcells, struct sk_buff *skb)
{
- struct gro_cell *cell = gcells->cells;
+ struct gro_cell *cell;
struct net_device *dev = skb->dev;
- if (!cell || skb_cloned(skb) || !(dev->features & NETIF_F_GRO)) {
+ if (!gcells->cells || 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;
+ cell = this_cpu_ptr(gcells->cells);
if (skb_queue_len(&cell->napi_skbs) > netdev_max_backlog) {
atomic_long_inc(&dev->rx_dropped);
@@ -72,15 +70,12 @@ static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *de
{
int i;
- gcells->gro_cells_mask = roundup_pow_of_two(netif_get_num_default_rss_queues()) - 1;
- gcells->cells = kcalloc(gcells->gro_cells_mask + 1,
- sizeof(struct gro_cell),
- GFP_KERNEL);
+ gcells->cells = alloc_percpu(struct gro_cell);
if (!gcells->cells)
return -ENOMEM;
- for (i = 0; i <= gcells->gro_cells_mask; i++) {
- struct gro_cell *cell = gcells->cells + i;
+ for_each_possible_cpu(i) {
+ struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
skb_queue_head_init(&cell->napi_skbs);
netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
@@ -91,16 +86,16 @@ static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *de
static inline void gro_cells_destroy(struct gro_cells *gcells)
{
- struct gro_cell *cell = gcells->cells;
int i;
- if (!cell)
+ if (!gcells->cells)
return;
- for (i = 0; i <= gcells->gro_cells_mask; i++,cell++) {
+ for_each_possible_cpu(i) {
+ struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
netif_napi_del(&cell->napi);
skb_queue_purge(&cell->napi_skbs);
}
- kfree(gcells->cells);
+ free_percpu(gcells->cells);
gcells->cells = NULL;
}