Re: [PATCH net-next] net: hns: optimize XGE capability by reducing cpu usage

From: Yankejian (Hackim Yim)
Date: Tue Dec 08 2015 - 01:23:13 EST




On 2015/12/7 16:58, Du, Fan wrote:
>
>
> On 2015/12/5 15:32, yankejian wrote:
>> here is the patch raising the performance of XGE by:
>> 1)changes the way page management method for enet momery, and
>> 2)reduces the count of rmb, and
>> 3)adds Memory prefetching
>
> Any numbers on how much it boost performance?
>

it is almost the same as 82599.

>> Signed-off-by: yankejian <yankejian@xxxxxxxxxx>
>> ---
>> drivers/net/ethernet/hisilicon/hns/hnae.h | 5 +-
>> drivers/net/ethernet/hisilicon/hns/hns_ae_adapt.c | 1 -
>> drivers/net/ethernet/hisilicon/hns/hns_enet.c | 79 +++++++++++++++--------
>> 3 files changed, 55 insertions(+), 30 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/hisilicon/hns/hnae.h b/drivers/net/ethernet/hisilicon/hns/hnae.h
>> index d1f3316..6ca94dc 100644
>> --- a/drivers/net/ethernet/hisilicon/hns/hnae.h
>> +++ b/drivers/net/ethernet/hisilicon/hns/hnae.h
>> @@ -341,7 +341,8 @@ struct hnae_queue {
>> void __iomem *io_base;
>> phys_addr_t phy_base;
>> struct hnae_ae_dev *dev; /* the device who use this queue */
>> - struct hnae_ring rx_ring, tx_ring;
>> + struct hnae_ring rx_ring ____cacheline_internodealigned_in_smp;
>> + struct hnae_ring tx_ring ____cacheline_internodealigned_in_smp;
>> struct hnae_handle *handle;
>> };
>>
>> @@ -597,11 +598,9 @@ static inline void hnae_replace_buffer(struct hnae_ring *ring, int i,
>> struct hnae_desc_cb *res_cb)
>> {
>> struct hnae_buf_ops *bops = ring->q->handle->bops;
>> - struct hnae_desc_cb tmp_cb = ring->desc_cb[i];
>>
>> bops->unmap_buffer(ring, &ring->desc_cb[i]);
>> ring->desc_cb[i] = *res_cb;
>> - *res_cb = tmp_cb;
>> ring->desc[i].addr = (__le64)ring->desc_cb[i].dma;
>> ring->desc[i].rx.ipoff_bnum_pid_flag = 0;
>> }
>> diff --git a/drivers/net/ethernet/hisilicon/hns/hns_ae_adapt.c b/drivers/net/ethernet/hisilicon/hns/hns_ae_adapt.c
>> index 77c6edb..522b264 100644
>> --- a/drivers/net/ethernet/hisilicon/hns/hns_ae_adapt.c
>> +++ b/drivers/net/ethernet/hisilicon/hns/hns_ae_adapt.c
>> @@ -341,7 +341,6 @@ void hns_ae_toggle_ring_irq(struct hnae_ring *ring, u32 mask)
>> else
>> flag = RCB_INT_FLAG_RX;
>>
>> - hns_rcb_int_clr_hw(ring->q, flag);
>> hns_rcb_int_ctrl_hw(ring->q, flag, mask);
>> }
>>
>> diff --git a/drivers/net/ethernet/hisilicon/hns/hns_enet.c b/drivers/net/ethernet/hisilicon/hns/hns_enet.c
>> index cad2663..e2be510 100644
>> --- a/drivers/net/ethernet/hisilicon/hns/hns_enet.c
>> +++ b/drivers/net/ethernet/hisilicon/hns/hns_enet.c
>> @@ -33,6 +33,7 @@
>>
>> #define RCB_IRQ_NOT_INITED 0
>> #define RCB_IRQ_INITED 1
>> +#define HNS_BUFFER_SIZE_2048 2048
>>
>> #define BD_MAX_SEND_SIZE 8191
>> #define SKB_TMP_LEN(SKB) \
>> @@ -491,13 +492,51 @@ static unsigned int hns_nic_get_headlen(unsigned char *data, u32 flag,
>> return max_size;
>> }
>>
>> -static void
>> -hns_nic_reuse_page(struct hnae_desc_cb *desc_cb, int tsize, int last_offset)
>> +static void hns_nic_reuse_page(struct sk_buff *skb, int i,
>> + struct hnae_ring *ring, int pull_len,
>> + struct hnae_desc_cb *desc_cb)
>> {
>> + struct hnae_desc *desc;
>> + int truesize, size;
>> + int last_offset = 0;
>> +
>> + desc = &ring->desc[ring->next_to_clean];
>> + size = le16_to_cpu(desc->rx.size);
>> +
>> +#if (PAGE_SIZE < 8192)
>> + if (hnae_buf_size(ring) == HNS_BUFFER_SIZE_2048) {
>> + truesize = hnae_buf_size(ring);
>> + } else {
>> + truesize = ALIGN(size, L1_CACHE_BYTES);
>> + last_offset = hnae_page_size(ring) - hnae_buf_size(ring);
>> + }
>> +
>> +#else
>> + truesize = ALIGN(size, L1_CACHE_BYTES);
>> + last_offset = hnae_page_size(ring) - hnae_buf_size(ring);
>> +#endif
>> +
>> + skb_add_rx_frag(skb, i, desc_cb->priv, desc_cb->page_offset + pull_len,
>> + size - pull_len, truesize - pull_len);
>> +
>> /* avoid re-using remote pages,flag default unreuse */
>> if (likely(page_to_nid(desc_cb->priv) == numa_node_id())) {
>> +#if (PAGE_SIZE < 8192)
>> + if (hnae_buf_size(ring) == HNS_BUFFER_SIZE_2048) {
>> + /* if we are only owner of page we can reuse it */
>> + if (likely(page_count(desc_cb->priv) == 1)) {
>> + /* flip page offset to other buffer */
>> + desc_cb->page_offset ^= truesize;
>> +
>> + desc_cb->reuse_flag = 1;
>> + /* bump ref count on page before it is given*/
>> + get_page(desc_cb->priv);
>> + }
>> + return;
>> + }
>> +#endif
>> /* move offset up to the next cache line */
>> - desc_cb->page_offset += tsize;
>> + desc_cb->page_offset += truesize;
>>
>> if (desc_cb->page_offset <= last_offset) {
>> desc_cb->reuse_flag = 1;
>> @@ -529,11 +568,10 @@ static int hns_nic_poll_rx_skb(struct hns_nic_ring_data *ring_data,
>> struct hnae_desc *desc;
>> struct hnae_desc_cb *desc_cb;
>> unsigned char *va;
>> - int bnum, length, size, i, truesize, last_offset;
>> + int bnum, length, i;
>> int pull_len;
>> u32 bnum_flag;
>>
>> - last_offset = hnae_page_size(ring) - hnae_buf_size(ring);
>> desc = &ring->desc[ring->next_to_clean];
>> desc_cb = &ring->desc_cb[ring->next_to_clean];
>>
>> @@ -555,17 +593,12 @@ static int hns_nic_poll_rx_skb(struct hns_nic_ring_data *ring_data,
>> return -ENOMEM;
>> }
>>
>> + prefetchw(skb->data);
>> length = le16_to_cpu(desc->rx.pkt_len);
>> bnum_flag = le32_to_cpu(desc->rx.ipoff_bnum_pid_flag);
>> priv->ops.get_rxd_bnum(bnum_flag, &bnum);
>> *out_bnum = bnum;
>>
>> - /* we will be copying header into skb->data in
>> - * pskb_may_pull so it is in our interest to prefetch
>> - * it now to avoid a possible cache miss
>> - */
>> - prefetchw(skb->data);
>> -
>> if (length <= HNS_RX_HEAD_SIZE) {
>> memcpy(__skb_put(skb, length), va, ALIGN(length, sizeof(long)));
>>
>> @@ -588,13 +621,7 @@ static int hns_nic_poll_rx_skb(struct hns_nic_ring_data *ring_data,
>> memcpy(__skb_put(skb, pull_len), va,
>> ALIGN(pull_len, sizeof(long)));
>>
>> - size = le16_to_cpu(desc->rx.size);
>> - truesize = ALIGN(size, L1_CACHE_BYTES);
>> - skb_add_rx_frag(skb, 0, desc_cb->priv,
>> - desc_cb->page_offset + pull_len,
>> - size - pull_len, truesize - pull_len);
>> -
>> - hns_nic_reuse_page(desc_cb, truesize, last_offset);
>> + hns_nic_reuse_page(skb, 0, ring, pull_len, desc_cb);
>> ring_ptr_move_fw(ring, next_to_clean);
>>
>> if (unlikely(bnum >= (int)MAX_SKB_FRAGS)) { /* check err*/
>> @@ -604,13 +631,8 @@ static int hns_nic_poll_rx_skb(struct hns_nic_ring_data *ring_data,
>> for (i = 1; i < bnum; i++) {
>> desc = &ring->desc[ring->next_to_clean];
>> desc_cb = &ring->desc_cb[ring->next_to_clean];
>> - size = le16_to_cpu(desc->rx.size);
>> - truesize = ALIGN(size, L1_CACHE_BYTES);
>> - skb_add_rx_frag(skb, i, desc_cb->priv,
>> - desc_cb->page_offset,
>> - size, truesize);
>>
>> - hns_nic_reuse_page(desc_cb, truesize, last_offset);
>> + hns_nic_reuse_page(skb, i, ring, 0, desc_cb);
>> ring_ptr_move_fw(ring, next_to_clean);
>> }
>> }
>> @@ -750,9 +772,10 @@ recv:
>> /* make all data has been write before submit */
>> if (recv_pkts < budget) {
>> ex_num = readl_relaxed(ring->io_base + RCB_REG_FBDNUM);
>> - rmb(); /*complete read rx ring bd number*/
>> +
>> if (ex_num > clean_count) {
>> num += ex_num - clean_count;
>> + rmb(); /*complete read rx ring bd number*/
>> goto recv;
>> }
>> }
>> @@ -849,8 +872,11 @@ static int hns_nic_tx_poll_one(struct hns_nic_ring_data *ring_data,
>>
>> bytes = 0;
>> pkts = 0;
>> - while (head != ring->next_to_clean)
>> + while (head != ring->next_to_clean) {
>> hns_nic_reclaim_one_desc(ring, &bytes, &pkts);
>> + /* issue prefetch for next Tx descriptor */
>> + prefetch(&ring->desc_cb[ring->next_to_clean]);
>> + }
>>
>> NETIF_TX_UNLOCK(ndev);
>>
>> @@ -926,6 +952,7 @@ static int hns_nic_common_poll(struct napi_struct *napi, int budget)
>> ring_data->ring, 0);
>>
>> ring_data->fini_process(ring_data);
>> + return 0;
>> }
>>
>> return clean_complete;
>>
>
> .
>


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