gro_cells: remove spinlock protecting receive queues
authorEric Dumazet <edumazet@google.com>
Mon, 31 Aug 2015 20:57:34 +0000 (13:57 -0700)
committerDavid S. Miller <davem@davemloft.net>
Mon, 31 Aug 2015 22:17:17 +0000 (15:17 -0700)
As David pointed out, spinlock are no longer needed
to protect the per cpu queues used in gro cells infrastructure.

Also use new napi_complete_done() API so that gro_flush_timeout
tweaks have an effect.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/net/gro_cells.h

index 0f712c0bc0bf27a910ca224ba050de5e7135fb30..cf6c74550baa53af7bfe6a8c0079174a85ac917d 100644 (file)
@@ -32,37 +32,28 @@ static inline void gro_cells_receive(struct gro_cells *gcells, struct sk_buff *s
                return;
        }
 
-       /* We run in BH context */
-       spin_lock(&cell->napi_skbs.lock);
-
        __skb_queue_tail(&cell->napi_skbs, skb);
        if (skb_queue_len(&cell->napi_skbs) == 1)
                napi_schedule(&cell->napi);
-
-       spin_unlock(&cell->napi_skbs.lock);
 }
 
-/* called unser BH context */
+/* called under BH context */
 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;
 
-       spin_lock(&cell->napi_skbs.lock);
        while (work_done < budget) {
                skb = __skb_dequeue(&cell->napi_skbs);
                if (!skb)
                        break;
-               spin_unlock(&cell->napi_skbs.lock);
                napi_gro_receive(napi, skb);
                work_done++;
-               spin_lock(&cell->napi_skbs.lock);
        }
 
        if (work_done < budget)
-               napi_complete(napi);
-       spin_unlock(&cell->napi_skbs.lock);
+               napi_complete_done(napi, work_done);
        return work_done;
 }
 
@@ -77,7 +68,7 @@ static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *de
        for_each_possible_cpu(i) {
                struct gro_cell *cell = per_cpu_ptr(gcells->cells, i);
 
-               skb_queue_head_init(&cell->napi_skbs);
+               __skb_queue_head_init(&cell->napi_skbs);
                netif_napi_add(dev, &cell->napi, gro_cell_poll, 64);
                napi_enable(&cell->napi);
        }
@@ -92,8 +83,9 @@ static inline void gro_cells_destroy(struct gro_cells *gcells)
                return;
        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);
+               __skb_queue_purge(&cell->napi_skbs);
        }
        free_percpu(gcells->cells);
        gcells->cells = NULL;