diff options
Diffstat (limited to 'drivers/net')
-rw-r--r-- | drivers/net/xen-netback/common.h | 1 | ||||
-rw-r--r-- | drivers/net/xen-netback/netback.c | 107 |
2 files changed, 3 insertions, 105 deletions
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index 5f1fda4..589fa25 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -251,7 +251,6 @@ struct xenvif { struct xenvif_rx_cb { unsigned long expires; int meta_slots_used; - bool full_coalesce; }; #define XENVIF_RX_CB(skb) ((struct xenvif_rx_cb *)(skb)->cb) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 908e65e..49322b6 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -233,51 +233,6 @@ static void xenvif_rx_queue_drop_expired(struct xenvif_queue *queue) } } -/* - * Returns true if we should start a new receive buffer instead of - * adding 'size' bytes to a buffer which currently contains 'offset' - * bytes. - */ -static bool start_new_rx_buffer(int offset, unsigned long size, int head, - bool full_coalesce) -{ - /* simple case: we have completely filled the current buffer. */ - if (offset == MAX_BUFFER_OFFSET) - return true; - - /* - * complex case: start a fresh buffer if the current frag - * would overflow the current buffer but only if: - * (i) this frag would fit completely in the next buffer - * and (ii) there is already some data in the current buffer - * and (iii) this is not the head buffer. - * and (iv) there is no need to fully utilize the buffers - * - * Where: - * - (i) stops us splitting a frag into two copies - * unless the frag is too large for a single buffer. - * - (ii) stops us from leaving a buffer pointlessly empty. - * - (iii) stops us leaving the first buffer - * empty. Strictly speaking this is already covered - * by (ii) but is explicitly checked because - * netfront relies on the first buffer being - * non-empty and can crash otherwise. - * - (iv) is needed for skbs which can use up more than MAX_SKB_FRAGS - * slot - * - * This means we will effectively linearise small - * frags but do not needlessly split large buffers - * into multiple copies tend to give large frags their - * own buffers as before. - */ - BUG_ON(size > MAX_BUFFER_OFFSET); - if ((offset + size > MAX_BUFFER_OFFSET) && offset && !head && - !full_coalesce) - return true; - - return false; -} - struct netrx_pending_operations { unsigned copy_prod, copy_cons; unsigned meta_prod, meta_cons; @@ -336,24 +291,13 @@ static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb BUG_ON(offset >= PAGE_SIZE); BUG_ON(npo->copy_off > MAX_BUFFER_OFFSET); - bytes = PAGE_SIZE - offset; + if (npo->copy_off == MAX_BUFFER_OFFSET) + meta = get_next_rx_buffer(queue, npo); + bytes = PAGE_SIZE - offset; if (bytes > size) bytes = size; - if (start_new_rx_buffer(npo->copy_off, - bytes, - *head, - XENVIF_RX_CB(skb)->full_coalesce)) { - /* - * Netfront requires there to be some data in the head - * buffer. - */ - BUG_ON(*head); - - meta = get_next_rx_buffer(queue, npo); - } - if (npo->copy_off + bytes > MAX_BUFFER_OFFSET) bytes = MAX_BUFFER_OFFSET - npo->copy_off; @@ -652,60 +596,15 @@ static void xenvif_rx_action(struct xenvif_queue *queue) while (xenvif_rx_ring_slots_available(queue, XEN_NETBK_RX_SLOTS_MAX) && (skb = xenvif_rx_dequeue(queue)) != NULL) { - RING_IDX max_slots_needed; RING_IDX old_req_cons; RING_IDX ring_slots_used; - int i; queue->last_rx_time = jiffies; - /* We need a cheap worse case estimate for the number of - * slots we'll use. - */ - - max_slots_needed = DIV_ROUND_UP(offset_in_page(skb->data) + - skb_headlen(skb), - PAGE_SIZE); - for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { - unsigned int size; - unsigned int offset; - - size = skb_frag_size(&skb_shinfo(skb)->frags[i]); - offset = skb_shinfo(skb)->frags[i].page_offset; - - /* For a worse-case estimate we need to factor in - * the fragment page offset as this will affect the - * number of times xenvif_gop_frag_copy() will - * call start_new_rx_buffer(). - */ - max_slots_needed += DIV_ROUND_UP(offset + size, - PAGE_SIZE); - } - - /* To avoid the estimate becoming too pessimal for some - * frontends that limit posted rx requests, cap the estimate - * at MAX_SKB_FRAGS. In this case netback will fully coalesce - * the skb into the provided slots. - */ - if (max_slots_needed > MAX_SKB_FRAGS) { - max_slots_needed = MAX_SKB_FRAGS; - XENVIF_RX_CB(skb)->full_coalesce = true; - } else { - XENVIF_RX_CB(skb)->full_coalesce = false; - } - - /* We may need one more slot for GSO metadata */ - if (skb_is_gso(skb) && - (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4 || - skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)) - max_slots_needed++; - old_req_cons = queue->rx.req_cons; XENVIF_RX_CB(skb)->meta_slots_used = xenvif_gop_skb(skb, &npo, queue); ring_slots_used = queue->rx.req_cons - old_req_cons; - BUG_ON(ring_slots_used > max_slots_needed); - __skb_queue_tail(&rxq, skb); } |