From 67e303e0c7683957eb4e530453705a43a6d4f966 Mon Sep 17 00:00:00 2001 From: VSR Burru Date: Mon, 6 Mar 2017 18:45:59 -0800 Subject: liquidio: improve UDP TX performance Improve UDP TX performance by: * reducing the ring size from 2K to 512 * replacing the numerous streaming DMA allocations for info buffers and gather lists with one large consistent DMA allocation per ring BQL is not effective here. We reduced the ring size because there is heavy overhead with dma_map_single every so often. With iommu=on, dma_map_single in PF Tx data path was taking longer time (~700usec) for every ~250 packets. Debugged intel_iommu code, and found that PF driver is utilizing too many static IO virtual address mapping entries (for gather list entries and info buffers): about 100K entries for two PF's each using 8 rings. Also, finding an empty entry (in rbtree of device domain's iova mapping in kernel) during Tx path becomes a bottleneck every so often; the loop to find the empty entry goes through over 40K iterations; this is too costly and was the major overhead. Overhead is low when this loop quits quickly. Netperf benchmark numbers before and after patch: PF UDP TX +--------+--------+------------+------------+---------+ | | | Before | After | | | Number | | Patch | Patch | | | of | Packet | Throughput | Throughput | Percent | | Flows | Size | (Gbps) | (Gbps) | Change | +--------+--------+------------+------------+---------+ | | 360 | 0.52 | 0.93 | +78.9 | | 1 | 1024 | 1.62 | 2.84 | +75.3 | | | 1518 | 2.44 | 4.21 | +72.5 | +--------+--------+------------+------------+---------+ | | 360 | 0.45 | 1.59 | +253.3 | | 4 | 1024 | 1.34 | 5.48 | +308.9 | | | 1518 | 2.27 | 8.31 | +266.1 | +--------+--------+------------+------------+---------+ | | 360 | 0.40 | 1.61 | +302.5 | | 8 | 1024 | 1.64 | 4.24 | +158.5 | | | 1518 | 2.87 | 6.52 | +127.2 | +--------+--------+------------+------------+---------+ VF UDP TX +--------+--------+------------+------------+---------+ | | | Before | After | | | Number | | Patch | Patch | | | of | Packet | Throughput | Throughput | Percent | | Flows | Size | (Gbps) | (Gbps) | Change | +--------+--------+------------+------------+---------+ | | 360 | 1.28 | 1.49 | +16.4 | | 1 | 1024 | 4.44 | 4.39 | -1.1 | | | 1518 | 6.08 | 6.51 | +7.1 | +--------+--------+------------+------------+---------+ | | 360 | 2.35 | 2.35 | 0.0 | | 4 | 1024 | 6.41 | 8.07 | +25.9 | | | 1518 | 9.56 | 9.54 | -0.2 | +--------+--------+------------+------------+---------+ | | 360 | 3.41 | 3.65 | +7.0 | | 8 | 1024 | 9.35 | 9.34 | -0.1 | | | 1518 | 9.56 | 9.57 | +0.1 | +--------+--------+------------+------------+---------+ Signed-off-by: VSR Burru Signed-off-by: Felix Manlunas Signed-off-by: Derek Chickles Signed-off-by: Raghu Vatsavayi Signed-off-by: David S. Miller --- drivers/net/ethernet/cavium/liquidio/lio_main.c | 110 ++++++++++++------------ 1 file changed, 55 insertions(+), 55 deletions(-) (limited to 'drivers/net/ethernet/cavium/liquidio/lio_main.c') diff --git a/drivers/net/ethernet/cavium/liquidio/lio_main.c b/drivers/net/ethernet/cavium/liquidio/lio_main.c index be9c0e3f5ade..92f46b1375c3 100644 --- a/drivers/net/ethernet/cavium/liquidio/lio_main.c +++ b/drivers/net/ethernet/cavium/liquidio/lio_main.c @@ -152,7 +152,7 @@ struct octnic_gather { */ struct octeon_sg_entry *sg; - u64 sg_dma_ptr; + dma_addr_t sg_dma_ptr; }; struct handshake { @@ -734,6 +734,9 @@ static void delete_glists(struct lio *lio) struct octnic_gather *g; int i; + kfree(lio->glist_lock); + lio->glist_lock = NULL; + if (!lio->glist) return; @@ -741,23 +744,26 @@ static void delete_glists(struct lio *lio) do { g = (struct octnic_gather *) list_delete_head(&lio->glist[i]); - if (g) { - if (g->sg) { - dma_unmap_single(&lio->oct_dev-> - pci_dev->dev, - g->sg_dma_ptr, - g->sg_size, - DMA_TO_DEVICE); - kfree((void *)((unsigned long)g->sg - - g->adjust)); - } + if (g) kfree(g); - } } while (g); + + if (lio->glists_virt_base && lio->glists_virt_base[i]) { + lio_dma_free(lio->oct_dev, + lio->glist_entry_size * lio->tx_qsize, + lio->glists_virt_base[i], + lio->glists_dma_base[i]); + } } - kfree((void *)lio->glist); - kfree((void *)lio->glist_lock); + kfree(lio->glists_virt_base); + lio->glists_virt_base = NULL; + + kfree(lio->glists_dma_base); + lio->glists_dma_base = NULL; + + kfree(lio->glist); + lio->glist = NULL; } /** @@ -772,13 +778,30 @@ static int setup_glists(struct octeon_device *oct, struct lio *lio, int num_iqs) lio->glist_lock = kcalloc(num_iqs, sizeof(*lio->glist_lock), GFP_KERNEL); if (!lio->glist_lock) - return 1; + return -ENOMEM; lio->glist = kcalloc(num_iqs, sizeof(*lio->glist), GFP_KERNEL); if (!lio->glist) { - kfree((void *)lio->glist_lock); - return 1; + kfree(lio->glist_lock); + lio->glist_lock = NULL; + return -ENOMEM; + } + + lio->glist_entry_size = + ROUNDUP8((ROUNDUP4(OCTNIC_MAX_SG) >> 2) * OCT_SG_ENTRY_SIZE); + + /* allocate memory to store virtual and dma base address of + * per glist consistent memory + */ + lio->glists_virt_base = kcalloc(num_iqs, sizeof(*lio->glists_virt_base), + GFP_KERNEL); + lio->glists_dma_base = kcalloc(num_iqs, sizeof(*lio->glists_dma_base), + GFP_KERNEL); + + if (!lio->glists_virt_base || !lio->glists_dma_base) { + delete_glists(lio); + return -ENOMEM; } for (i = 0; i < num_iqs; i++) { @@ -788,6 +811,16 @@ static int setup_glists(struct octeon_device *oct, struct lio *lio, int num_iqs) INIT_LIST_HEAD(&lio->glist[i]); + lio->glists_virt_base[i] = + lio_dma_alloc(oct, + lio->glist_entry_size * lio->tx_qsize, + &lio->glists_dma_base[i]); + + if (!lio->glists_virt_base[i]) { + delete_glists(lio); + return -ENOMEM; + } + for (j = 0; j < lio->tx_qsize; j++) { g = kzalloc_node(sizeof(*g), GFP_KERNEL, numa_node); @@ -796,43 +829,18 @@ static int setup_glists(struct octeon_device *oct, struct lio *lio, int num_iqs) if (!g) break; - g->sg_size = ((ROUNDUP4(OCTNIC_MAX_SG) >> 2) * - OCT_SG_ENTRY_SIZE); + g->sg = lio->glists_virt_base[i] + + (j * lio->glist_entry_size); - g->sg = kmalloc_node(g->sg_size + 8, - GFP_KERNEL, numa_node); - if (!g->sg) - g->sg = kmalloc(g->sg_size + 8, GFP_KERNEL); - if (!g->sg) { - kfree(g); - break; - } - - /* The gather component should be aligned on 64-bit - * boundary - */ - if (((unsigned long)g->sg) & 7) { - g->adjust = 8 - (((unsigned long)g->sg) & 7); - g->sg = (struct octeon_sg_entry *) - ((unsigned long)g->sg + g->adjust); - } - g->sg_dma_ptr = dma_map_single(&oct->pci_dev->dev, - g->sg, g->sg_size, - DMA_TO_DEVICE); - if (dma_mapping_error(&oct->pci_dev->dev, - g->sg_dma_ptr)) { - kfree((void *)((unsigned long)g->sg - - g->adjust)); - kfree(g); - break; - } + g->sg_dma_ptr = lio->glists_dma_base[i] + + (j * lio->glist_entry_size); list_add_tail(&g->list, &lio->glist[i]); } if (j != lio->tx_qsize) { delete_glists(lio); - return 1; + return -ENOMEM; } } @@ -1885,9 +1893,6 @@ static void free_netsgbuf(void *buf) i++; } - dma_sync_single_for_cpu(&lio->oct_dev->pci_dev->dev, - g->sg_dma_ptr, g->sg_size, DMA_TO_DEVICE); - iq = skb_iq(lio, skb); spin_lock(&lio->glist_lock[iq]); list_add_tail(&g->list, &lio->glist[iq]); @@ -1933,9 +1938,6 @@ static void free_netsgbuf_with_resp(void *buf) i++; } - dma_sync_single_for_cpu(&lio->oct_dev->pci_dev->dev, - g->sg_dma_ptr, g->sg_size, DMA_TO_DEVICE); - iq = skb_iq(lio, skb); spin_lock(&lio->glist_lock[iq]); @@ -3273,8 +3275,6 @@ static int liquidio_xmit(struct sk_buff *skb, struct net_device *netdev) i++; } - dma_sync_single_for_device(&oct->pci_dev->dev, g->sg_dma_ptr, - g->sg_size, DMA_TO_DEVICE); dptr = g->sg_dma_ptr; if (OCTEON_CN23XX_PF(oct)) -- cgit