From 9fa316261d7d9e79bcff84fb84ab498b9e7d93f4 Mon Sep 17 00:00:00 2001 From: Xavier Simonart Date: Sat, 13 Jan 2018 21:28:14 +0100 Subject: Fix latency accuracy and dumping latencies to file - Also changed lat_info.tx_packet_index to uint64_t, so also did it for task_lat.prev_tx_packet_index and n_loss. - Adjusted format strings accordingly, and fixed some other formats. - Adjusted overflow increment to 2^32 (i.e. UINT32_MAX + 1). - Replaced hard-coded 64 with ACCURACY_BUFFER_SIZE (still hard-coded in handle_gen.c). Change-Id: Ia59f36e17c0797a2a958dbe3b2ac420263473524 Signed-off-by: Xavier Simonart Signed-off-by: Patrice Buriez --- VNFs/DPPD-PROX/handle_lat.c | 273 +++++++++++++++++++++++++++++--------------- 1 file changed, 182 insertions(+), 91 deletions(-) (limited to 'VNFs/DPPD-PROX/handle_lat.c') diff --git a/VNFs/DPPD-PROX/handle_lat.c b/VNFs/DPPD-PROX/handle_lat.c index b50f9504..3962b21d 100644 --- a/VNFs/DPPD-PROX/handle_lat.c +++ b/VNFs/DPPD-PROX/handle_lat.c @@ -35,10 +35,11 @@ #include "prox_port_cfg.h" #define DEFAULT_BUCKET_SIZE 10 +#define ACCURACY_BUFFER_SIZE 64 struct lat_info { uint32_t rx_packet_index; - uint32_t tx_packet_index; + uint64_t tx_packet_index; uint32_t tx_err; uint32_t rx_err; uint64_t rx_time; @@ -54,28 +55,29 @@ struct lat_info { }; struct delayed_latency_entry { - uint32_t rx_packet_idx; + uint32_t rx_packet_id; + uint32_t tx_packet_id; + uint32_t packet_id; + uint8_t generator_id; uint64_t pkt_rx_time; uint64_t pkt_tx_time; uint64_t rx_time_err; }; -struct delayed_latency { - struct delayed_latency_entry entries[64]; -}; - -static struct delayed_latency_entry *delayed_latency_get(struct delayed_latency *delayed_latency, uint32_t rx_packet_idx) +static struct delayed_latency_entry *delayed_latency_get(struct delayed_latency_entry **delayed_latency_entries, uint8_t generator_id, uint32_t packet_id) { - if (delayed_latency->entries[rx_packet_idx % 64].rx_packet_idx == rx_packet_idx) - return &delayed_latency->entries[rx_packet_idx % 64]; + struct delayed_latency_entry *delayed_latency_entry = &delayed_latency_entries[generator_id][packet_id % ACCURACY_BUFFER_SIZE]; + if (delayed_latency_entry->packet_id == packet_id) + return delayed_latency_entry; else return NULL; } -static struct delayed_latency_entry *delayed_latency_create(struct delayed_latency *delayed_latency, uint32_t rx_packet_idx) +static struct delayed_latency_entry *delayed_latency_create(struct delayed_latency_entry **delayed_latency_entries, uint8_t generator_id, uint32_t packet_id) { - delayed_latency->entries[rx_packet_idx % 64].rx_packet_idx = rx_packet_idx; - return &delayed_latency->entries[rx_packet_idx % 64]; + struct delayed_latency_entry *delayed_latency_entry = &delayed_latency_entries[generator_id][packet_id % ACCURACY_BUFFER_SIZE]; + delayed_latency_entry->packet_id = packet_id; + return delayed_latency_entry; } struct rx_pkt_meta_data { @@ -89,7 +91,7 @@ struct task_lat { uint64_t limit; uint64_t rx_packet_index; uint64_t last_pkts_tsc; - struct delayed_latency delayed_latency; + struct delayed_latency_entry **delayed_latency_entries; struct lat_info *latency_buffer; uint32_t latency_buffer_idx; uint32_t latency_buffer_size; @@ -107,14 +109,16 @@ struct task_lat { struct early_loss_detect *eld; struct rx_pkt_meta_data *rx_pkt_meta; uint64_t link_speed; + // Following fields are only used when starting or stopping, not in general runtime + uint64_t *prev_tx_packet_index; FILE *fp_rx; FILE *fp_tx; struct prox_port_cfg *port; }; -static uint32_t abs_diff(uint32_t a, uint32_t b) +static uint32_t diff_or_zero(uint32_t a, uint32_t b) { - return a < b? UINT32_MAX - (b - a - 1) : a - b; + return a < b? 0 : a - b; } struct lat_test *task_lat_get_latency_meassurement(struct task_lat *task) @@ -143,34 +147,81 @@ static int compare_tx_time(const void *val1, const void *val2) const struct lat_info *ptr1 = val1; const struct lat_info *ptr2 = val2; - return ptr1->tx_time - ptr2->tx_time; + return ptr1->tx_time > ptr2->tx_time ? 1 : -1; } -static int compare_queue_id(const void *val1, const void *val2) +static int compare_tx_packet_index(const void *val1, const void *val2) { - return compare_tx_time(val1, val2); + const struct lat_info *ptr1 = val1; + const struct lat_info *ptr2 = val2; + + return ptr1->tx_packet_index > ptr2->tx_packet_index ? 1 : -1; } -static void fix_latency_buffer_tx_time(struct lat_info *lat, uint32_t count) +static void fix_latency_buffer_tx_packet_index(struct lat_info *lat, uint32_t count) { - uint32_t id, time, old_id = 0, old_time = 0, n_overflow = 0; + uint32_t tx_packet_index, old_tx_packet_index = lat->tx_packet_index, n_overflow = 0; + uint32_t small = UINT32_MAX >> 1; + + lat++; - for (uint32_t i = 0; i < count; i++) { - id = lat->port_queue_id; - time = lat->tx_time; - if (id == old_id) { - // Same queue id as previous entry; time should always increase - if (time < old_time) { + /* Buffer is sorted so far by RX time. + * We might have packets being reordered by SUT. + * => consider small differences as re-order and big ones as overflow of tx_packet_index. + * Note that: + * - overflow only happens if receiving and storing 4 billions packets... + * - a absolute difference of less than 2 billion packets is not considered as an overflow + */ + for (uint32_t i = 1; i < count; i++) { + tx_packet_index = lat->tx_packet_index; + if (tx_packet_index > old_tx_packet_index) { + if (tx_packet_index - old_tx_packet_index < small) { + // The diff is small => increasing index count + } else { + // The diff is big => it is more likely that the previous packet was overflow + n_overflow--; + } + } else { + if (old_tx_packet_index - tx_packet_index < small) { + // The diff is small => packet reorder + } else { + // The diff is big => it is more likely that this is an overflow n_overflow++; } - lat->tx_time += UINT32_MAX * n_overflow; - old_time = time; + } + lat->tx_packet_index += ((uint64_t)UINT32_MAX + 1) * n_overflow; + old_tx_packet_index = tx_packet_index; + lat++; + } +} + +static void fix_latency_buffer_tx_time(struct lat_info *lat, uint32_t count) +{ + uint32_t tx_time, old_tx_time = lat->tx_time, n_overflow = 0; + uint32_t small = UINT32_MAX >> 1; + lat++; + + /* + * Same algorithm as above, but with time. + * Note that: + * - overflow happens after 4 billions "cycles" (shifted by LATENCY_ACCURACY) = ~4sec + * - a absolute difference up to 2 billion (shifted) cycles (~=2sec) is not considered as an overflow + * => algorithm does not work if receiving less than 1 packet every 2 seconds + */ + for (uint32_t i = 1; i < count; i++) { + tx_time = lat->tx_time; + if (tx_time > old_tx_time) { + if (tx_time - old_tx_time > small) { + n_overflow--; + } } else { - // Different queue_id, time starts again at 0 - old_id = id; - old_time = 0; - n_overflow = 0; + if (old_tx_time - tx_time > small) { + n_overflow++; + } } + lat->tx_time += ((uint64_t)UINT32_MAX + 1) * n_overflow; + old_tx_time = tx_time; + lat++; } } @@ -206,7 +257,7 @@ static uint64_t lat_latency_buffer_get_min_tsc(struct task_lat *task) static uint64_t lat_info_get_lat_tsc(struct lat_info *lat_info) { - uint64_t lat = abs_diff(lat_info->rx_time, lat_info->tx_time); + uint64_t lat = diff_or_zero(lat_info->rx_time, lat_info->tx_time); return lat << LATENCY_ACCURACY; } @@ -223,18 +274,18 @@ static uint64_t lat_info_get_rx_err_tsc(const struct lat_info *lat_info) static uint64_t lat_info_get_rx_tsc(const struct lat_info *lat_info) { - return ((uint64_t)lat_info) << LATENCY_ACCURACY; + return ((uint64_t)lat_info->rx_time) << LATENCY_ACCURACY; } static uint64_t lat_info_get_tx_tsc(const struct lat_info *lat_info) { - return ((uint64_t)lat_info) << LATENCY_ACCURACY; + return ((uint64_t)lat_info->tx_time) << LATENCY_ACCURACY; } static void lat_write_latency_to_file(struct task_lat *task) { uint64_t min_tsc; - uint32_t n_loss; + uint64_t n_loss; min_tsc = lat_latency_buffer_get_min_tsc(task); @@ -247,7 +298,7 @@ static void lat_write_latency_to_file(struct task_lat *task) uint64_t rx_tsc = lat_info_get_rx_tsc(lat_info); uint64_t tx_tsc = lat_info_get_tx_tsc(lat_info); - fprintf(task->fp_rx, "%u%d;%d;%ld;%lu;%lu\n", + fprintf(task->fp_rx, "%u;%u;%lu;%lu;%lu;%lu\n", lat_info->rx_packet_index, lat_info->port_queue_id, lat_info->tx_packet_index, @@ -257,19 +308,27 @@ static void lat_write_latency_to_file(struct task_lat *task) } // To detect dropped packets, we need to sort them based on TX - plogx_info("Sorting packets based on queue_id\n"); - qsort (task->latency_buffer, task->latency_buffer_idx, sizeof(struct lat_info), compare_queue_id); - plogx_info("Adapting tx_time\n"); - fix_latency_buffer_tx_time(task->latency_buffer, task->latency_buffer_idx); - plogx_info("Sorting packets based on tx_time\n"); - qsort (task->latency_buffer, task->latency_buffer_idx, sizeof(struct lat_info), compare_tx_time); - plogx_info("Sorted packets based on tx_time\n"); + if (task->unique_id_pos) { + plogx_info("Adapting tx_packet_index\n"); + fix_latency_buffer_tx_packet_index(task->latency_buffer, task->latency_buffer_idx); + plogx_info("Sorting packets based on tx_packet_index\n"); + qsort (task->latency_buffer, task->latency_buffer_idx, sizeof(struct lat_info), compare_tx_packet_index); + plogx_info("Sorted packets based on packet_index\n"); + } else { + plogx_info("Adapting tx_time\n"); + fix_latency_buffer_tx_time(task->latency_buffer, task->latency_buffer_idx); + plogx_info("Sorting packets based on tx_time\n"); + qsort (task->latency_buffer, task->latency_buffer_idx, sizeof(struct lat_info), compare_tx_time); + plogx_info("Sorted packets based on packet_time\n"); + } // A packet is marked as dropped if 2 packets received from the same queue are not consecutive fprintf(task->fp_tx, "Latency stats for %u packets, sorted by tx time\n", task->latency_buffer_idx); fprintf(task->fp_tx, "queue;tx index; rx index; lat (nsec);tx time; rx time; tx_err;rx_err\n"); - uint32_t prev_tx_packet_index = -1; + for (uint32_t i = 0; i < task->generator_count;i++) + task->prev_tx_packet_index[i] = -1; + for (uint32_t i = 0; i < task->latency_buffer_idx; i++) { struct lat_info *lat_info = &task->latency_buffer[i]; uint64_t lat_tsc = lat_info_get_lat_tsc(lat_info); @@ -278,19 +337,25 @@ static void lat_write_latency_to_file(struct task_lat *task) uint64_t rx_tsc = lat_info_get_rx_tsc(lat_info); uint64_t tx_tsc = lat_info_get_tx_tsc(lat_info); - /* Packet n + 64 delivers the TX error for packet n, - hence the last 64 packets do no have TX error. */ - if (i + 64 >= task->latency_buffer_idx) { + /* Packet n + ACCURACY_BUFFER_SIZE delivers the TX error for packet n, + hence the last ACCURACY_BUFFER_SIZE packets do no have TX error. */ + if (i + ACCURACY_BUFFER_SIZE >= task->latency_buffer_idx) { tx_err_tsc = 0; } + + if (lat_info->port_queue_id >= task->generator_count) { + plog_err("Unexpected generator id %u for packet %lu - skipping packet\n", + lat_info->port_queue_id, lat_info->tx_packet_index); + continue; + } // Log dropped packet - n_loss = lat_info->tx_packet_index - prev_tx_packet_index - 1; + n_loss = lat_info->tx_packet_index - task->prev_tx_packet_index[lat_info->port_queue_id] - 1; if (n_loss) - fprintf(task->fp_tx, "===> %d;%d;0;0;0;0; lost %d packets <===\n", + fprintf(task->fp_tx, "===> %u;%lu;0;0;0;0;0;0 lost %lu packets <===\n", lat_info->port_queue_id, lat_info->tx_packet_index - n_loss, n_loss); // Log next packet - fprintf(task->fp_tx, "%d;%d;%u;%lu;%lu;%lu;%lu;%lu\n", + fprintf(task->fp_tx, "%u;%lu;%u;%lu;%lu;%lu;%lu;%lu", lat_info->port_queue_id, lat_info->tx_packet_index, lat_info->rx_packet_index, @@ -300,7 +365,7 @@ static void lat_write_latency_to_file(struct task_lat *task) tsc_to_nsec(tx_err_tsc), tsc_to_nsec(rx_err_tsc)); #ifdef LAT_DEBUG - fprintf(task->fp_tx, ";%d from %d;%lu;%lu;%lu", + fprintf(task->fp_tx, ";%u from %u;%lu;%lu;%lu", lat_info->id_in_bulk, lat_info->bulk_size, tsc_to_nsec(lat_info->begin - min_tsc), @@ -308,7 +373,7 @@ static void lat_write_latency_to_file(struct task_lat *task) tsc_to_nsec(lat_info->after - min_tsc)); #endif fprintf(task->fp_tx, "\n"); - prev_tx_packet_index = lat_info->tx_packet_index; + task->prev_tx_packet_index[lat_info->port_queue_id] = lat_info->tx_packet_index; } fflush(task->fp_rx); fflush(task->fp_tx); @@ -340,21 +405,16 @@ static void task_lat_store_lat_debug(struct task_lat *task, uint32_t rx_packet_i } #endif -static void task_lat_store_lat_buf(struct task_lat *task, uint64_t rx_packet_index, struct unique_id *unique_id, uint64_t rx_time, uint64_t tx_time, uint64_t rx_err, uint64_t tx_err) +static void task_lat_store_lat_buf(struct task_lat *task, uint64_t rx_packet_index, uint64_t rx_time, uint64_t tx_time, uint64_t rx_err, uint64_t tx_err, uint32_t packet_id, uint8_t generator_id) { struct lat_info *lat_info; - uint8_t generator_id = 0; - uint32_t packet_index = 0; - - if (unique_id) - unique_id_get(unique_id, &generator_id, &packet_index); /* If unique_id_pos is specified then latency is stored per packet being sent. Lost packets are detected runtime, and latency stored for those packets will be 0 */ lat_info = &task->latency_buffer[task->latency_buffer_idx++]; - lat_info->rx_packet_index = task->latency_buffer_idx - 1; - lat_info->tx_packet_index = packet_index; + lat_info->rx_packet_index = rx_packet_index; + lat_info->tx_packet_index = packet_id; lat_info->port_queue_id = generator_id; lat_info->rx_time = rx_time; lat_info->tx_time = tx_time; @@ -403,8 +463,6 @@ static void lat_test_add_lost(struct lat_test *lat_test, uint64_t lost_packets) static void lat_test_add_latency(struct lat_test *lat_test, uint64_t lat_tsc, uint64_t error) { - lat_test->tot_all_pkts++; - if (error > lat_test->accuracy_limit_tsc) return; lat_test->tot_pkts++; @@ -436,16 +494,16 @@ static int task_lat_can_store_latency(struct task_lat *task) return task->latency_buffer_idx < task->latency_buffer_size; } -static void task_lat_store_lat(struct task_lat *task, uint64_t rx_packet_index, uint64_t rx_time, uint64_t tx_time, uint64_t rx_error, uint64_t tx_error, struct unique_id *unique_id) +static void task_lat_store_lat(struct task_lat *task, uint64_t rx_packet_index, uint64_t rx_time, uint64_t tx_time, uint64_t rx_error, uint64_t tx_error, uint32_t packet_id, uint8_t generator_id) { if (tx_time == 0) return; - uint32_t lat_tsc = abs_diff(rx_time, tx_time) << LATENCY_ACCURACY; + uint32_t lat_tsc = diff_or_zero(rx_time, tx_time) << LATENCY_ACCURACY; lat_test_add_latency(task->lat_test, lat_tsc, rx_error + tx_error); if (task_lat_can_store_latency(task)) { - task_lat_store_lat_buf(task, rx_packet_index, unique_id, rx_time, tx_time, rx_error, tx_error); + task_lat_store_lat_buf(task, rx_packet_index, rx_time, tx_time, rx_error, tx_error, packet_id, generator_id); } } @@ -473,8 +531,6 @@ static int handle_lat_bulk(struct task_base *tbase, struct rte_mbuf **mbufs, uin struct rte_mbuf *mbuf = mbufs[j]; task->rx_pkt_meta[j].hdr = rte_pktmbuf_mtod(mbuf, uint8_t *); } - for (uint16_t j = 0; j < n_pkts; ++j) { - } if (task->sig) { for (uint16_t j = 0; j < n_pkts; ++j) { @@ -508,6 +564,7 @@ static int handle_lat_bulk(struct task_base *tbase, struct rte_mbuf **mbufs, uin struct unique_id *unique_id = NULL; struct delayed_latency_entry *delayed_latency_entry; + uint32_t packet_id, generator_id; for (uint16_t j = 0; j < n_pkts; ++j) { struct rx_pkt_meta_data *rx_pkt_meta = &task->rx_pkt_meta[j]; @@ -520,41 +577,45 @@ static int handle_lat_bulk(struct task_base *tbase, struct rte_mbuf **mbufs, uin unique_id = (struct unique_id *)(hdr + task->unique_id_pos); uint32_t n_loss = task_lat_early_loss_detect(task, unique_id); + packet_id = unique_id->packet_id; + generator_id = unique_id->generator_id; lat_test_add_lost(task->lat_test, n_loss); + } else { + packet_id = task->rx_packet_index; + generator_id = 0; } + task->lat_test->tot_all_pkts++; /* If accuracy is enabled, latency is reported with a - delay of 64 packets since the generator puts the - accuracy for packet N into packet N + 64. The delay + delay of ACCURACY_BUFFER_SIZE packets since the generator puts the + accuracy for packet N into packet N + ACCURACY_BUFFER_SIZE. The delay ensures that all reported latencies have both rx and tx error. */ if (task->accur_pos) { tx_time_err = *(uint32_t *)(hdr + task->accur_pos); - delayed_latency_entry = delayed_latency_get(&task->delayed_latency, task->rx_packet_index - 64); + delayed_latency_entry = delayed_latency_get(task->delayed_latency_entries, generator_id, packet_id - ACCURACY_BUFFER_SIZE); if (delayed_latency_entry) { task_lat_store_lat(task, - task->rx_packet_index, + delayed_latency_entry->rx_packet_id, delayed_latency_entry->pkt_rx_time, delayed_latency_entry->pkt_tx_time, delayed_latency_entry->rx_time_err, tx_time_err, - unique_id); + delayed_latency_entry->tx_packet_id, + delayed_latency_entry->generator_id); } - delayed_latency_entry = delayed_latency_create(&task->delayed_latency, task->rx_packet_index); + delayed_latency_entry = delayed_latency_create(task->delayed_latency_entries, generator_id, packet_id); delayed_latency_entry->pkt_rx_time = pkt_rx_time; delayed_latency_entry->pkt_tx_time = pkt_tx_time; delayed_latency_entry->rx_time_err = rx_time_err; + delayed_latency_entry->rx_packet_id = task->rx_packet_index; + delayed_latency_entry->tx_packet_id = packet_id; + delayed_latency_entry->generator_id = generator_id; } else { - task_lat_store_lat(task, - task->rx_packet_index, - pkt_rx_time, - pkt_tx_time, - 0, - 0, - unique_id); + task_lat_store_lat(task, task->rx_packet_index, pkt_rx_time, pkt_tx_time, 0, 0, packet_id, generator_id); } task->rx_packet_index++; } @@ -577,29 +638,39 @@ static void init_task_lat_latency_buffer(struct task_lat *task, uint32_t core_id latency_buffer_mem_size = sizeof(struct lat_info) * task->latency_buffer_size; task->latency_buffer = prox_zmalloc(latency_buffer_mem_size, socket_id); - PROX_PANIC(task->latency_buffer == NULL, "Failed to allocate %ld kbytes for %s\n", latency_buffer_mem_size / 1024, name); + PROX_PANIC(task->latency_buffer == NULL, "Failed to allocate %zu kbytes for latency_buffer\n", latency_buffer_mem_size / 1024); - sprintf(name, "latency.rx_%d.txt", core_id); + sprintf(name, "latency.rx_%u.txt", core_id); task->fp_rx = fopen(name, "w+"); PROX_PANIC(task->fp_rx == NULL, "Failed to open %s\n", name); - sprintf(name, "latency.tx_%d.txt", core_id); + sprintf(name, "latency.tx_%u.txt", core_id); task->fp_tx = fopen(name, "w+"); PROX_PANIC(task->fp_tx == NULL, "Failed to open %s\n", name); + + task->prev_tx_packet_index = prox_zmalloc(sizeof(task->prev_tx_packet_index[0]) * task->generator_count, socket_id); + PROX_PANIC(task->prev_tx_packet_index == NULL, "Failed to allocated prev_tx_packet_index\n"); } -static void task_lat_init_eld(struct task_lat *task, uint8_t socket_id) +static void task_init_generator_count(struct task_lat *task) { uint8_t *generator_count = prox_sh_find_system("generator_count"); - size_t eld_mem_size; - if (generator_count == NULL) - task->generator_count = 0; - else + if (generator_count == NULL) { + task->generator_count = 1; + plog_info("\tNo generators found, hard-coding to %u generators\n", task->generator_count); + } else task->generator_count = *generator_count; + plog_info("\tLatency using %u generators\n", task->generator_count); +} + +static void task_lat_init_eld(struct task_lat *task, uint8_t socket_id) +{ + size_t eld_mem_size; eld_mem_size = sizeof(task->eld[0]) * task->generator_count; task->eld = prox_zmalloc(eld_mem_size, socket_id); + PROX_PANIC(task->eld == NULL, "Failed to allocate eld\n"); } void task_lat_set_accuracy_limit(struct task_lat *task, uint32_t accuracy_limit_nsec) @@ -615,7 +686,7 @@ static void lat_start(struct task_base *tbase) // task->port->link->speed reports the link speed in Mbps e.g. 40k for a 40 Gbps NIC // task->link_speed reported link speed in Bytes per sec. task->link_speed = task->port->link_speed * 125000L; - plog_info("\tReceiving at %ld Mbps\n", 8 * task->link_speed / 1000000); + plog_info("\tReceiving at %lu Mbps\n", 8 * task->link_speed / 1000000); } } @@ -632,14 +703,34 @@ static void init_task_lat(struct task_base *tbase, struct task_args *targ) task->unique_id_pos = targ->packet_id_pos; task->latency_buffer_size = targ->latency_buffer_size; + task_init_generator_count(task); + if (task->latency_buffer_size) { init_task_lat_latency_buffer(task, targ->lconf->id); } - if (targ->bucket_size < LATENCY_ACCURACY) { + if (targ->bucket_size < DEFAULT_BUCKET_SIZE) { targ->bucket_size = DEFAULT_BUCKET_SIZE; } + if (task->accur_pos) { + task->delayed_latency_entries = prox_zmalloc(sizeof(*task->delayed_latency_entries) * task->generator_count , socket_id); + PROX_PANIC(task->delayed_latency_entries == NULL, "Failed to allocate array for storing delayed latency entries\n"); + for (uint i = 0; i < task->generator_count; i++) { + task->delayed_latency_entries[i] = prox_zmalloc(sizeof(**task->delayed_latency_entries) * ACCURACY_BUFFER_SIZE, socket_id); + PROX_PANIC(task->delayed_latency_entries[i] == NULL, "Failed to allocate array for storing delayed latency entries\n"); + } + if (task->unique_id_pos == 0) { + /* When using accuracy feature, the accuracy from TX is written ACCURACY_BUFFER_SIZE packets later + * We can only retrieve the good packet if a packet id is written to it. + * Otherwise we will use the packet RECEIVED ACCURACY_BUFFER_SIZE packets ago which is OK if + * packets are not re-ordered. If packets are re-ordered, then the matching between + * the tx accuracy znd the latency is wrong. + */ + plog_warn("\tWhen accuracy feature is used, a unique id should ideally also be used\n"); + } + } + task->lt[0].bucket_size = targ->bucket_size - LATENCY_ACCURACY; task->lt[1].bucket_size = targ->bucket_size - LATENCY_ACCURACY; if (task->unique_id_pos) { -- cgit 1.2.3-korg