diff options
author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-11-14 06:05:34 +0000 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2011-11-14 14:13:30 -0500 |
commit | e52fcb2462ac484e6dd6e68869536609f0216938 (patch) | |
tree | 794407ff242481d5d09e3e669cabfe129d80f6df /drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | |
parent | b2b5ce9d1ccf1c45f8ac68e5d901112ab76ba199 (diff) | |
download | op-kernel-dev-e52fcb2462ac484e6dd6e68869536609f0216938.zip op-kernel-dev-e52fcb2462ac484e6dd6e68869536609f0216938.tar.gz |
bnx2x: uses build_skb() in receive path
bnx2x uses following formula to compute its rx_buf_sz :
dev->mtu + 2*L1_CACHE_BYTES + 14 + 8 + 8 + 2
Then core network adds NET_SKB_PAD and SKB_DATA_ALIGN(sizeof(struct
skb_shared_info))
Final allocated size for skb head on x86_64 (L1_CACHE_BYTES = 64,
MTU=1500) : 2112 bytes : SLUB/SLAB round this to 4096 bytes.
Since skb truesize is then bigger than SK_MEM_QUANTUM, we have lot of
false sharing because of mem_reclaim in UDP stack.
One possible way to half truesize is to reduce the need by 64 bytes
(2112 -> 2048 bytes)
Instead of allocating a full cache line at the end of packet for
alignment, we can use the fact that skb_shared_info sits at the end of
skb->head, and we can use this room, if we convert bnx2x to new
build_skb() infrastructure.
skb_shared_info will be initialized after hardware finished its
transfert, so we can eventually overwrite the final padding.
Using build_skb() also reduces cache line misses in the driver, since we
use cache hot skb instead of cold ones. Number of in-flight sk_buff
structures is lower, they are recycled while still hot.
Performance results :
(820.000 pps on a rx UDP monothread benchmark, instead of 720.000 pps)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Eilon Greenstein <eilong@broadcom.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Tom Herbert <therbert@google.com>
CC: Jamal Hadi Salim <hadi@mojatatu.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Thomas Graf <tgraf@infradead.org>
CC: Herbert Xu <herbert@gondor.apana.org.au>
CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c')
-rw-r--r-- | drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 267 |
1 files changed, 126 insertions, 141 deletions
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c index 13dad92..0d60b9e 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c @@ -294,8 +294,21 @@ static void bnx2x_update_sge_prod(struct bnx2x_fastpath *fp, fp->last_max_sge, fp->rx_sge_prod); } +/* Set Toeplitz hash value in the skb using the value from the + * CQE (calculated by HW). + */ +static u32 bnx2x_get_rxhash(const struct bnx2x *bp, + const struct eth_fast_path_rx_cqe *cqe) +{ + /* Set Toeplitz hash from CQE */ + if ((bp->dev->features & NETIF_F_RXHASH) && + (cqe->status_flags & ETH_FAST_PATH_RX_CQE_RSS_HASH_FLG)) + return le32_to_cpu(cqe->rss_hash_result); + return 0; +} + static void bnx2x_tpa_start(struct bnx2x_fastpath *fp, u16 queue, - struct sk_buff *skb, u16 cons, u16 prod, + u16 cons, u16 prod, struct eth_fast_path_rx_cqe *cqe) { struct bnx2x *bp = fp->bp; @@ -310,9 +323,9 @@ static void bnx2x_tpa_start(struct bnx2x_fastpath *fp, u16 queue, if (tpa_info->tpa_state != BNX2X_TPA_STOP) BNX2X_ERR("start of bin not in stop [%d]\n", queue); - /* Try to map an empty skb from the aggregation info */ + /* Try to map an empty data buffer from the aggregation info */ mapping = dma_map_single(&bp->pdev->dev, - first_buf->skb->data, + first_buf->data + NET_SKB_PAD, fp->rx_buf_size, DMA_FROM_DEVICE); /* * ...if it fails - move the skb from the consumer to the producer @@ -322,15 +335,15 @@ static void bnx2x_tpa_start(struct bnx2x_fastpath *fp, u16 queue, if (unlikely(dma_mapping_error(&bp->pdev->dev, mapping))) { /* Move the BD from the consumer to the producer */ - bnx2x_reuse_rx_skb(fp, cons, prod); + bnx2x_reuse_rx_data(fp, cons, prod); tpa_info->tpa_state = BNX2X_TPA_ERROR; return; } - /* move empty skb from pool to prod */ - prod_rx_buf->skb = first_buf->skb; + /* move empty data from pool to prod */ + prod_rx_buf->data = first_buf->data; dma_unmap_addr_set(prod_rx_buf, mapping, mapping); - /* point prod_bd to new skb */ + /* point prod_bd to new data */ prod_bd->addr_hi = cpu_to_le32(U64_HI(mapping)); prod_bd->addr_lo = cpu_to_le32(U64_LO(mapping)); @@ -344,6 +357,7 @@ static void bnx2x_tpa_start(struct bnx2x_fastpath *fp, u16 queue, tpa_info->tpa_state = BNX2X_TPA_START; tpa_info->len_on_bd = le16_to_cpu(cqe->len_on_bd); tpa_info->placement_offset = cqe->placement_offset; + tpa_info->rxhash = bnx2x_get_rxhash(bp, cqe); #ifdef BNX2X_STOP_ON_ERROR fp->tpa_queue_used |= (1 << queue); @@ -471,11 +485,12 @@ static void bnx2x_tpa_stop(struct bnx2x *bp, struct bnx2x_fastpath *fp, { struct bnx2x_agg_info *tpa_info = &fp->tpa_info[queue]; struct sw_rx_bd *rx_buf = &tpa_info->first_buf; - u8 pad = tpa_info->placement_offset; + u32 pad = tpa_info->placement_offset; u16 len = tpa_info->len_on_bd; - struct sk_buff *skb = rx_buf->skb; + struct sk_buff *skb = NULL; + u8 *data = rx_buf->data; /* alloc new skb */ - struct sk_buff *new_skb; + u8 *new_data; u8 old_tpa_state = tpa_info->tpa_state; tpa_info->tpa_state = BNX2X_TPA_STOP; @@ -486,18 +501,18 @@ static void bnx2x_tpa_stop(struct bnx2x *bp, struct bnx2x_fastpath *fp, if (old_tpa_state == BNX2X_TPA_ERROR) goto drop; - /* Try to allocate the new skb */ - new_skb = netdev_alloc_skb(bp->dev, fp->rx_buf_size); + /* Try to allocate the new data */ + new_data = kmalloc(fp->rx_buf_size + NET_SKB_PAD, GFP_ATOMIC); /* Unmap skb in the pool anyway, as we are going to change pool entry status to BNX2X_TPA_STOP even if new skb allocation fails. */ dma_unmap_single(&bp->pdev->dev, dma_unmap_addr(rx_buf, mapping), fp->rx_buf_size, DMA_FROM_DEVICE); + if (likely(new_data)) + skb = build_skb(data); - if (likely(new_skb)) { - prefetch(skb); - prefetch(((char *)(skb)) + L1_CACHE_BYTES); + if (likely(skb)) { #ifdef BNX2X_STOP_ON_ERROR if (pad + len > fp->rx_buf_size) { @@ -509,8 +524,9 @@ static void bnx2x_tpa_stop(struct bnx2x *bp, struct bnx2x_fastpath *fp, } #endif - skb_reserve(skb, pad); + skb_reserve(skb, pad + NET_SKB_PAD); skb_put(skb, len); + skb->rxhash = tpa_info->rxhash; skb->protocol = eth_type_trans(skb, bp->dev); skb->ip_summed = CHECKSUM_UNNECESSARY; @@ -526,8 +542,8 @@ static void bnx2x_tpa_stop(struct bnx2x *bp, struct bnx2x_fastpath *fp, } - /* put new skb in bin */ - rx_buf->skb = new_skb; + /* put new data in bin */ + rx_buf->data = new_data; return; } @@ -539,19 +555,6 @@ drop: fp->eth_q_stats.rx_skb_alloc_failed++; } -/* Set Toeplitz hash value in the skb using the value from the - * CQE (calculated by HW). - */ -static inline void bnx2x_set_skb_rxhash(struct bnx2x *bp, union eth_rx_cqe *cqe, - struct sk_buff *skb) -{ - /* Set Toeplitz hash from CQE */ - if ((bp->dev->features & NETIF_F_RXHASH) && - (cqe->fast_path_cqe.status_flags & - ETH_FAST_PATH_RX_CQE_RSS_HASH_FLG)) - skb->rxhash = - le32_to_cpu(cqe->fast_path_cqe.rss_hash_result); -} int bnx2x_rx_int(struct bnx2x_fastpath *fp, int budget) { @@ -594,6 +597,7 @@ int bnx2x_rx_int(struct bnx2x_fastpath *fp, int budget) u8 cqe_fp_flags; enum eth_rx_cqe_type cqe_fp_type; u16 len, pad; + u8 *data; #ifdef BNX2X_STOP_ON_ERROR if (unlikely(bp->panic)) @@ -604,13 +608,6 @@ int bnx2x_rx_int(struct bnx2x_fastpath *fp, int budget) bd_prod = RX_BD(bd_prod); bd_cons = RX_BD(bd_cons); - /* Prefetch the page containing the BD descriptor - at producer's index. It will be needed when new skb is - allocated */ - prefetch((void *)(PAGE_ALIGN((unsigned long) - (&fp->rx_desc_ring[bd_prod])) - - PAGE_SIZE + 1)); - cqe = &fp->rx_comp_ring[comp_ring_cons]; cqe_fp = &cqe->fast_path_cqe; cqe_fp_flags = cqe_fp->type_error_flags; @@ -626,125 +623,110 @@ int bnx2x_rx_int(struct bnx2x_fastpath *fp, int budget) if (unlikely(CQE_TYPE_SLOW(cqe_fp_type))) { bnx2x_sp_event(fp, cqe); goto next_cqe; + } + rx_buf = &fp->rx_buf_ring[bd_cons]; + data = rx_buf->data; - /* this is an rx packet */ - } else { - rx_buf = &fp->rx_buf_ring[bd_cons]; - skb = rx_buf->skb; - prefetch(skb); - - if (!CQE_TYPE_FAST(cqe_fp_type)) { + if (!CQE_TYPE_FAST(cqe_fp_type)) { #ifdef BNX2X_STOP_ON_ERROR - /* sanity check */ - if (fp->disable_tpa && - (CQE_TYPE_START(cqe_fp_type) || - CQE_TYPE_STOP(cqe_fp_type))) - BNX2X_ERR("START/STOP packet while " - "disable_tpa type %x\n", - CQE_TYPE(cqe_fp_type)); + /* sanity check */ + if (fp->disable_tpa && + (CQE_TYPE_START(cqe_fp_type) || + CQE_TYPE_STOP(cqe_fp_type))) + BNX2X_ERR("START/STOP packet while " + "disable_tpa type %x\n", + CQE_TYPE(cqe_fp_type)); #endif - if (CQE_TYPE_START(cqe_fp_type)) { - u16 queue = cqe_fp->queue_index; - DP(NETIF_MSG_RX_STATUS, - "calling tpa_start on queue %d\n", - queue); - - bnx2x_tpa_start(fp, queue, skb, - bd_cons, bd_prod, - cqe_fp); - - /* Set Toeplitz hash for LRO skb */ - bnx2x_set_skb_rxhash(bp, cqe, skb); - - goto next_rx; - - } else { - u16 queue = - cqe->end_agg_cqe.queue_index; - DP(NETIF_MSG_RX_STATUS, - "calling tpa_stop on queue %d\n", - queue); + if (CQE_TYPE_START(cqe_fp_type)) { + u16 queue = cqe_fp->queue_index; + DP(NETIF_MSG_RX_STATUS, + "calling tpa_start on queue %d\n", + queue); - bnx2x_tpa_stop(bp, fp, queue, - &cqe->end_agg_cqe, - comp_ring_cons); + bnx2x_tpa_start(fp, queue, + bd_cons, bd_prod, + cqe_fp); + goto next_rx; + } else { + u16 queue = + cqe->end_agg_cqe.queue_index; + DP(NETIF_MSG_RX_STATUS, + "calling tpa_stop on queue %d\n", + queue); + + bnx2x_tpa_stop(bp, fp, queue, + &cqe->end_agg_cqe, + comp_ring_cons); #ifdef BNX2X_STOP_ON_ERROR - if (bp->panic) - return 0; + if (bp->panic) + return 0; #endif - bnx2x_update_sge_prod(fp, cqe_fp); - goto next_cqe; - } + bnx2x_update_sge_prod(fp, cqe_fp); + goto next_cqe; } - /* non TPA */ - len = le16_to_cpu(cqe_fp->pkt_len); - pad = cqe_fp->placement_offset; - dma_sync_single_for_cpu(&bp->pdev->dev, + } + /* non TPA */ + len = le16_to_cpu(cqe_fp->pkt_len); + pad = cqe_fp->placement_offset; + dma_sync_single_for_cpu(&bp->pdev->dev, dma_unmap_addr(rx_buf, mapping), - pad + RX_COPY_THRESH, - DMA_FROM_DEVICE); - prefetch(((char *)(skb)) + L1_CACHE_BYTES); + pad + RX_COPY_THRESH, + DMA_FROM_DEVICE); + pad += NET_SKB_PAD; + prefetch(data + pad); /* speedup eth_type_trans() */ + /* is this an error packet? */ + if (unlikely(cqe_fp_flags & ETH_RX_ERROR_FALGS)) { + DP(NETIF_MSG_RX_ERR, + "ERROR flags %x rx packet %u\n", + cqe_fp_flags, sw_comp_cons); + fp->eth_q_stats.rx_err_discard_pkt++; + goto reuse_rx; + } - /* is this an error packet? */ - if (unlikely(cqe_fp_flags & ETH_RX_ERROR_FALGS)) { + /* Since we don't have a jumbo ring + * copy small packets if mtu > 1500 + */ + if ((bp->dev->mtu > ETH_MAX_PACKET_SIZE) && + (len <= RX_COPY_THRESH)) { + skb = netdev_alloc_skb_ip_align(bp->dev, len); + if (skb == NULL) { DP(NETIF_MSG_RX_ERR, - "ERROR flags %x rx packet %u\n", - cqe_fp_flags, sw_comp_cons); - fp->eth_q_stats.rx_err_discard_pkt++; + "ERROR packet dropped because of alloc failure\n"); + fp->eth_q_stats.rx_skb_alloc_failed++; goto reuse_rx; } - - /* Since we don't have a jumbo ring - * copy small packets if mtu > 1500 - */ - if ((bp->dev->mtu > ETH_MAX_PACKET_SIZE) && - (len <= RX_COPY_THRESH)) { - struct sk_buff *new_skb; - - new_skb = netdev_alloc_skb(bp->dev, len + pad); - if (new_skb == NULL) { - DP(NETIF_MSG_RX_ERR, - "ERROR packet dropped " - "because of alloc failure\n"); - fp->eth_q_stats.rx_skb_alloc_failed++; - goto reuse_rx; - } - - /* aligned copy */ - skb_copy_from_linear_data_offset(skb, pad, - new_skb->data + pad, len); - skb_reserve(new_skb, pad); - skb_put(new_skb, len); - - bnx2x_reuse_rx_skb(fp, bd_cons, bd_prod); - - skb = new_skb; - - } else - if (likely(bnx2x_alloc_rx_skb(bp, fp, bd_prod) == 0)) { + memcpy(skb->data, data + pad, len); + bnx2x_reuse_rx_data(fp, bd_cons, bd_prod); + } else { + if (likely(bnx2x_alloc_rx_data(bp, fp, bd_prod) == 0)) { dma_unmap_single(&bp->pdev->dev, - dma_unmap_addr(rx_buf, mapping), + dma_unmap_addr(rx_buf, mapping), fp->rx_buf_size, DMA_FROM_DEVICE); + skb = build_skb(data); + if (unlikely(!skb)) { + kfree(data); + fp->eth_q_stats.rx_skb_alloc_failed++; + goto next_rx; + } skb_reserve(skb, pad); - skb_put(skb, len); - } else { DP(NETIF_MSG_RX_ERR, "ERROR packet dropped because " "of alloc failure\n"); fp->eth_q_stats.rx_skb_alloc_failed++; reuse_rx: - bnx2x_reuse_rx_skb(fp, bd_cons, bd_prod); + bnx2x_reuse_rx_data(fp, bd_cons, bd_prod); goto next_rx; } + skb_put(skb, len); skb->protocol = eth_type_trans(skb, bp->dev); /* Set Toeplitz hash for a none-LRO skb */ - bnx2x_set_skb_rxhash(bp, cqe, skb); + skb->rxhash = bnx2x_get_rxhash(bp, cqe_fp); skb_checksum_none_assert(skb); @@ -767,7 +749,7 @@ reuse_rx: next_rx: - rx_buf->skb = NULL; + rx_buf->data = NULL; bd_cons = NEXT_RX_IDX(bd_cons); bd_prod = NEXT_RX_IDX(bd_prod); @@ -1013,9 +995,9 @@ void bnx2x_init_rx_rings(struct bnx2x *bp) struct sw_rx_bd *first_buf = &tpa_info->first_buf; - first_buf->skb = netdev_alloc_skb(bp->dev, - fp->rx_buf_size); - if (!first_buf->skb) { + first_buf->data = kmalloc(fp->rx_buf_size + NET_SKB_PAD, + GFP_ATOMIC); + if (!first_buf->data) { BNX2X_ERR("Failed to allocate TPA " "skb pool for queue[%d] - " "disabling TPA on this " @@ -1118,16 +1100,16 @@ static void bnx2x_free_rx_bds(struct bnx2x_fastpath *fp) for (i = 0; i < NUM_RX_BD; i++) { struct sw_rx_bd *rx_buf = &fp->rx_buf_ring[i]; - struct sk_buff *skb = rx_buf->skb; + u8 *data = rx_buf->data; - if (skb == NULL) + if (data == NULL) continue; dma_unmap_single(&bp->pdev->dev, dma_unmap_addr(rx_buf, mapping), fp->rx_buf_size, DMA_FROM_DEVICE); - rx_buf->skb = NULL; - dev_kfree_skb(skb); + rx_buf->data = NULL; + kfree(data); } } @@ -1509,6 +1491,7 @@ static inline void bnx2x_set_rx_buf_size(struct bnx2x *bp) for_each_queue(bp, i) { struct bnx2x_fastpath *fp = &bp->fp[i]; + u32 mtu; /* Always use a mini-jumbo MTU for the FCoE L2 ring */ if (IS_FCOE_IDX(i)) @@ -1518,13 +1501,15 @@ static inline void bnx2x_set_rx_buf_size(struct bnx2x *bp) * IP_HEADER_ALIGNMENT_PADDING to prevent a buffer * overrun attack. */ - fp->rx_buf_size = - BNX2X_FCOE_MINI_JUMBO_MTU + ETH_OVREHEAD + - BNX2X_FW_RX_ALIGN + IP_HEADER_ALIGNMENT_PADDING; + mtu = BNX2X_FCOE_MINI_JUMBO_MTU; else - fp->rx_buf_size = - bp->dev->mtu + ETH_OVREHEAD + - BNX2X_FW_RX_ALIGN + IP_HEADER_ALIGNMENT_PADDING; + mtu = bp->dev->mtu; + fp->rx_buf_size = BNX2X_FW_RX_ALIGN_START + + IP_HEADER_ALIGNMENT_PADDING + + ETH_OVREHEAD + + mtu + + BNX2X_FW_RX_ALIGN_END; + /* Note : rx_buf_size doesnt take into account NET_SKB_PAD */ } } |