From: Damjan Marion Date: Mon, 6 Mar 2017 20:51:00 +0000 (+0100) Subject: dpdk: dpdk-input optimizations and fixes X-Git-Tag: v17.04-rc1~83 X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=25f635852aee76255f7210c43d43668a80fdccce;p=vpp.git dpdk: dpdk-input optimizations and fixes - fix issue caused by assumption that ethertype starts at 0 - intoduce buffer templates to speed-up vlib_buffer_t metadata initialization - avoid check for multiseg buffers inside loop if multiseg is disabled - interleave prefetches to reduce load on L1 cache Change-Id: I3b76e6d3e1e15ed28f01625edb7fbe9f38112e03 Signed-off-by: Damjan Marion --- diff --git a/src/plugins/dpdk.am b/src/plugins/dpdk.am index 01383de60ae..f1a37ae2710 100644 --- a/src/plugins/dpdk.am +++ b/src/plugins/dpdk.am @@ -16,6 +16,10 @@ vppplugins_LTLIBRARIES += dpdk_plugin.la dpdk_plugin_la_LDFLAGS = $(AM_LDFLAGS) -Wl,--whole-archive,-l:libdpdk.a,--no-whole-archive,-lm,-ldl +# due to internal compiler error in GCC when compiling dpdk/device/node.c +# debug sysmbols level reduced to 1. See GCC PR #79953 for details +CFLAGS += -g1 + dpdk_plugin_la_SOURCES = \ dpdk/main.c \ dpdk/buffer.c \ diff --git a/src/plugins/dpdk/device/dpdk.h b/src/plugins/dpdk/device/dpdk.h index 092c7dca604..84f86ae28dd 100644 --- a/src/plugins/dpdk/device/dpdk.h +++ b/src/plugins/dpdk/device/dpdk.h @@ -338,6 +338,9 @@ typedef struct /* per-thread recycle lists */ u32 **recycle; + /* per-thread buffer templates */ + vlib_buffer_t *buffer_templates; + /* buffer flags template, configurable to enable/disable tcp / udp cksum */ u32 buffer_flags_template; diff --git a/src/plugins/dpdk/device/init.c b/src/plugins/dpdk/device/init.c index 85ecde25a23..110d74571b5 100755 --- a/src/plugins/dpdk/device/init.c +++ b/src/plugins/dpdk/device/init.c @@ -572,6 +572,21 @@ dpdk_lib_init (dpdk_main_t * dm) dm->buffer_flags_template &= ~(IP_BUFFER_L4_CHECKSUM_CORRECT | IP_BUFFER_L4_CHECKSUM_COMPUTED); + /* vlib_buffer_t template */ + vec_validate_aligned (dm->buffer_templates, tm->n_vlib_mains - 1, + CLIB_CACHE_LINE_BYTES); + for (i = 0; i < tm->n_vlib_mains; i++) + { + vlib_buffer_free_list_t *fl; + vlib_buffer_t *bt = vec_elt_at_index (dm->buffer_templates, i); + fl = vlib_buffer_get_free_list (vm, + VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX); + vlib_buffer_init_for_free_list (bt, fl); + bt->flags = dm->buffer_flags_template; + bt->current_data = -RTE_PKTMBUF_HEADROOM; + vnet_buffer (bt)->sw_if_index[VLIB_TX] = (u32) ~ 0; + } + for (i = 0; i < nports; i++) { u8 addr[6]; diff --git a/src/plugins/dpdk/device/node.c b/src/plugins/dpdk/device/node.c index 2120069e6f0..e8d502ca692 100644 --- a/src/plugins/dpdk/device/node.c +++ b/src/plugins/dpdk/device/node.c @@ -37,21 +37,21 @@ static char *dpdk_error_strings[] = { always_inline int vlib_buffer_is_ip4 (vlib_buffer_t * b) { - ethernet_header_t *h = (ethernet_header_t *) b->data; + ethernet_header_t *h = (ethernet_header_t *) vlib_buffer_get_current (b); return (h->type == clib_host_to_net_u16 (ETHERNET_TYPE_IP4)); } always_inline int vlib_buffer_is_ip6 (vlib_buffer_t * b) { - ethernet_header_t *h = (ethernet_header_t *) b->data; + ethernet_header_t *h = (ethernet_header_t *) vlib_buffer_get_current (b); return (h->type == clib_host_to_net_u16 (ETHERNET_TYPE_IP6)); } always_inline int vlib_buffer_is_mpls (vlib_buffer_t * b) { - ethernet_header_t *h = (ethernet_header_t *) b->data; + ethernet_header_t *h = (ethernet_header_t *) vlib_buffer_get_current (b); return (h->type == clib_host_to_net_u16 (ETHERNET_TYPE_MPLS_UNICAST)); } @@ -217,10 +217,35 @@ dpdk_prefetch_buffer (struct rte_mbuf *mb) } static_always_inline void -dpdk_prefetch_buffer_data (struct rte_mbuf *mb) +dpdk_prefetch_ethertype (struct rte_mbuf *mb) { - vlib_buffer_t *b = vlib_buffer_from_rte_mbuf (mb); - CLIB_PREFETCH (b->data, CLIB_CACHE_LINE_BYTES, STORE); + CLIB_PREFETCH (mb->buf_addr + mb->data_off + + STRUCT_OFFSET_OF (ethernet_header_t, type), + CLIB_CACHE_LINE_BYTES, LOAD); +} + + +/* + This function should fill 1st cacheline of vlib_buffer_t metadata with data + from buffer template. Instead of filling field by field, we construct + template and then use 128/256 bit vector instruction to copy data. + This code first loads whole cacheline into 4 128-bit registers (xmm) + or two 256 bit registers (ymm) and then stores data into all 4 buffers + efectively saving on register load operations. +*/ + +static_always_inline void +dpdk_buffer_init_from_template (void *d0, void *d1, void *d2, void *d3, + void *s) +{ + int i; + for (i = 0; i < 2; i++) + { + *(u8x32 *) (((u8 *) d0) + i * 32) = + *(u8x32 *) (((u8 *) d1) + i * 32) = + *(u8x32 *) (((u8 *) d2) + i * 32) = + *(u8x32 *) (((u8 *) d3) + i * 32) = *(u8x32 *) (((u8 *) s) + i * 32); + } } /* @@ -229,7 +254,8 @@ dpdk_prefetch_buffer_data (struct rte_mbuf *mb) */ static_always_inline u32 dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd, - vlib_node_runtime_t * node, u32 cpu_index, u16 queue_id) + vlib_node_runtime_t * node, u32 cpu_index, u16 queue_id, + int maybe_multiseg) { u32 n_buffers; u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT; @@ -239,7 +265,7 @@ dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd, uword n_rx_bytes = 0; u32 n_trace, trace_cnt __attribute__ ((unused)); vlib_buffer_free_list_t *fl; - u32 buffer_flags_template; + vlib_buffer_t *bt = vec_elt_at_index (dm->buffer_templates, cpu_index); if ((xd->flags & DPDK_DEVICE_FLAG_ADMIN_UP) == 0) return 0; @@ -251,8 +277,6 @@ dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd, return 0; } - buffer_flags_template = dm->buffer_flags_template; - vec_reset_length (xd->d_trace_buffers[cpu_index]); trace_cnt = n_trace = vlib_get_trace_count (vm, node); @@ -272,33 +296,44 @@ dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd, fl = vlib_buffer_get_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX); + /* Update buffer template */ + vnet_buffer (bt)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index; + bt->error = node->errors[DPDK_ERROR_NONE]; + mb_index = 0; while (n_buffers > 0) { vlib_buffer_t *b0, *b1, *b2, *b3; - u32 bi0, next0, l3_offset0; - u32 bi1, next1, l3_offset1; - u32 bi2, next2, l3_offset2; - u32 bi3, next3, l3_offset3; + u32 bi0, next0; + u32 bi1, next1; + u32 bi2, next2; + u32 bi3, next3; u8 error0, error1, error2, error3; u64 or_ol_flags; vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); - while (n_buffers > 8 && n_left_to_next > 4) + while (n_buffers >= 12 && n_left_to_next >= 4) { - struct rte_mbuf *mb0 = xd->rx_vectors[queue_id][mb_index]; - struct rte_mbuf *mb1 = xd->rx_vectors[queue_id][mb_index + 1]; - struct rte_mbuf *mb2 = xd->rx_vectors[queue_id][mb_index + 2]; - struct rte_mbuf *mb3 = xd->rx_vectors[queue_id][mb_index + 3]; + struct rte_mbuf *mb0, *mb1, *mb2, *mb3; - dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 4]); - dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 5]); - dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 6]); - dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 7]); + /* prefetches are interleaved with the rest of the code to reduce + pressure on L1 cache */ + dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 8]); + dpdk_prefetch_ethertype (xd->rx_vectors[queue_id][mb_index + 4]); - if (xd->flags & DPDK_DEVICE_FLAG_MAYBE_MULTISEG) + mb0 = xd->rx_vectors[queue_id][mb_index]; + mb1 = xd->rx_vectors[queue_id][mb_index + 1]; + mb2 = xd->rx_vectors[queue_id][mb_index + 2]; + mb3 = xd->rx_vectors[queue_id][mb_index + 3]; + + ASSERT (mb0); + ASSERT (mb1); + ASSERT (mb2); + ASSERT (mb3); + + if (maybe_multiseg) { if (PREDICT_FALSE (mb0->nb_segs > 1)) dpdk_prefetch_buffer (mb0->next); @@ -310,22 +345,29 @@ dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd, dpdk_prefetch_buffer (mb3->next); } - ASSERT (mb0); - ASSERT (mb1); - ASSERT (mb2); - ASSERT (mb3); - - or_ol_flags = (mb0->ol_flags | mb1->ol_flags | - mb2->ol_flags | mb3->ol_flags); b0 = vlib_buffer_from_rte_mbuf (mb0); b1 = vlib_buffer_from_rte_mbuf (mb1); b2 = vlib_buffer_from_rte_mbuf (mb2); b3 = vlib_buffer_from_rte_mbuf (mb3); - vlib_buffer_init_for_free_list (b0, fl); - vlib_buffer_init_for_free_list (b1, fl); - vlib_buffer_init_for_free_list (b2, fl); - vlib_buffer_init_for_free_list (b3, fl); + dpdk_buffer_init_from_template (b0, b1, b2, b3, bt); + + dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 9]); + dpdk_prefetch_ethertype (xd->rx_vectors[queue_id][mb_index + 5]); + + /* current_data must be set to -RTE_PKTMBUF_HEADROOM in template */ + b0->current_data += mb0->data_off; + b1->current_data += mb1->data_off; + b2->current_data += mb2->data_off; + b3->current_data += mb3->data_off; + + b0->current_length = mb0->data_len; + b1->current_length = mb1->data_len; + b2->current_length = mb2->data_len; + b3->current_length = mb3->data_len; + + dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 10]); + dpdk_prefetch_ethertype (xd->rx_vectors[queue_id][mb_index + 7]); bi0 = vlib_get_buffer_index (vm, b0); bi1 = vlib_get_buffer_index (vm, b1); @@ -345,21 +387,17 @@ dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd, } else { - /* prefetch packet data for faster access to the ethertype */ - dpdk_prefetch_buffer_data (xd->rx_vectors[queue_id] - [mb_index + 4]); - dpdk_prefetch_buffer_data (xd->rx_vectors[queue_id] - [mb_index + 5]); - dpdk_prefetch_buffer_data (xd->rx_vectors[queue_id] - [mb_index + 6]); - dpdk_prefetch_buffer_data (xd->rx_vectors[queue_id] - [mb_index + 7]); next0 = dpdk_rx_next_from_etype (mb0, b0); next1 = dpdk_rx_next_from_etype (mb1, b1); next2 = dpdk_rx_next_from_etype (mb2, b2); next3 = dpdk_rx_next_from_etype (mb3, b3); } + dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 11]); + dpdk_prefetch_ethertype (xd->rx_vectors[queue_id][mb_index + 6]); + + or_ol_flags = (mb0->ol_flags | mb1->ol_flags | + mb2->ol_flags | mb3->ol_flags); if (PREDICT_FALSE (or_ol_flags & PKT_RX_IP_CKSUM_BAD)) { dpdk_rx_error_from_mb (mb0, &next0, &error0); @@ -371,46 +409,11 @@ dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd, b2->error = node->errors[error2]; b3->error = node->errors[error3]; } - else - { - b0->error = b1->error = node->errors[DPDK_ERROR_NONE]; - b2->error = b3->error = node->errors[DPDK_ERROR_NONE]; - } - l3_offset0 = device_input_next_node_advance[next0]; - l3_offset1 = device_input_next_node_advance[next1]; - l3_offset2 = device_input_next_node_advance[next2]; - l3_offset3 = device_input_next_node_advance[next3]; - - b0->current_data = l3_offset0 + mb0->data_off; - b1->current_data = l3_offset1 + mb1->data_off; - b2->current_data = l3_offset2 + mb2->data_off; - b3->current_data = l3_offset3 + mb3->data_off; - - b0->current_data -= RTE_PKTMBUF_HEADROOM; - b1->current_data -= RTE_PKTMBUF_HEADROOM; - b2->current_data -= RTE_PKTMBUF_HEADROOM; - b3->current_data -= RTE_PKTMBUF_HEADROOM; - - b0->current_length = mb0->data_len - l3_offset0; - b1->current_length = mb1->data_len - l3_offset1; - b2->current_length = mb2->data_len - l3_offset2; - b3->current_length = mb3->data_len - l3_offset3; - - b0->flags = buffer_flags_template; - b1->flags = buffer_flags_template; - b2->flags = buffer_flags_template; - b3->flags = buffer_flags_template; - - vnet_buffer (b0)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index; - vnet_buffer (b1)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index; - vnet_buffer (b2)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index; - vnet_buffer (b3)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index; - - vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0; - vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0; - vnet_buffer (b2)->sw_if_index[VLIB_TX] = (u32) ~ 0; - vnet_buffer (b3)->sw_if_index[VLIB_TX] = (u32) ~ 0; + vlib_buffer_advance (b0, device_input_next_node_advance[next0]); + vlib_buffer_advance (b1, device_input_next_node_advance[next1]); + vlib_buffer_advance (b2, device_input_next_node_advance[next2]); + vlib_buffer_advance (b3, device_input_next_node_advance[next3]); n_rx_bytes += mb0->pkt_len; n_rx_bytes += mb1->pkt_len; @@ -418,7 +421,7 @@ dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd, n_rx_bytes += mb3->pkt_len; /* Process subsequent segments of multi-segment packets */ - if (xd->flags & DPDK_DEVICE_FLAG_MAYBE_MULTISEG) + if (maybe_multiseg) { dpdk_process_subseq_segs (vm, b0, mb0, fl); dpdk_process_subseq_segs (vm, b1, mb1, fl); @@ -452,6 +455,13 @@ dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd, { struct rte_mbuf *mb0 = xd->rx_vectors[queue_id][mb_index]; + if (PREDICT_TRUE (n_buffers > 3)) + { + dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 2]); + dpdk_prefetch_ethertype (xd->rx_vectors[queue_id] + [mb_index + 1]); + } + ASSERT (mb0); b0 = vlib_buffer_from_rte_mbuf (mb0); @@ -460,7 +470,11 @@ dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd, if (PREDICT_FALSE (mb0->nb_segs > 1)) dpdk_prefetch_buffer (mb0->next); - vlib_buffer_init_for_free_list (b0, fl); + clib_memcpy (b0, bt, CLIB_CACHE_LINE_BYTES); + + ASSERT (b0->current_data == -RTE_PKTMBUF_HEADROOM); + b0->current_data += mb0->data_off; + b0->current_length = mb0->data_len; bi0 = vlib_get_buffer_index (vm, b0); @@ -474,18 +488,9 @@ dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd, next0 = dpdk_rx_next_from_etype (mb0, b0); dpdk_rx_error_from_mb (mb0, &next0, &error0); - b0->error = node->errors[error0]; - - l3_offset0 = device_input_next_node_advance[next0]; - b0->current_data = l3_offset0; - b0->current_data += mb0->data_off - RTE_PKTMBUF_HEADROOM; - b0->current_length = mb0->data_len - l3_offset0; + vlib_buffer_advance (b0, device_input_next_node_advance[next0]); - b0->flags = buffer_flags_template; - - vnet_buffer (b0)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index; - vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0; n_rx_bytes += mb0->pkt_len; /* Process subsequent segments of multi-segment packets */ @@ -604,7 +609,10 @@ dpdk_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * f) vec_foreach (dq, dm->devices_by_cpu[cpu_index]) { xd = vec_elt_at_index(dm->devices, dq->device); - n_rx_packets += dpdk_device_input (dm, xd, node, cpu_index, dq->queue_id); + if (xd->flags & DPDK_DEVICE_FLAG_MAYBE_MULTISEG) + n_rx_packets += dpdk_device_input (dm, xd, node, cpu_index, dq->queue_id, /* maybe_multiseg */ 1); + else + n_rx_packets += dpdk_device_input (dm, xd, node, cpu_index, dq->queue_id, /* maybe_multiseg */ 0); } /* *INDENT-ON* */