diff options
Diffstat (limited to 'drivers/net/ethernet/intel/ice/ice_txrx.c')
| -rw-r--r-- | drivers/net/ethernet/intel/ice/ice_txrx.c | 135 |
1 files changed, 63 insertions, 72 deletions
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c index a1dcde49eb99..79043fec0187 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c @@ -1097,19 +1097,69 @@ static int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget) return failure ? budget : (int)total_rx_pkts; } -static unsigned int ice_itr_divisor(struct ice_port_info *pi) +/** + * ice_adjust_itr_by_size_and_speed - Adjust ITR based on current traffic + * @port_info: port_info structure containing the current link speed + * @avg_pkt_size: average size of Tx or Rx packets based on clean routine + * @itr: itr value to update + * + * Calculate how big of an increment should be applied to the ITR value passed + * in based on wmem_default, SKB overhead, Ethernet overhead, and the current + * link speed. + * + * The following is a calculation derived from: + * wmem_default / (size + overhead) = desired_pkts_per_int + * rate / bits_per_byte / (size + Ethernet overhead) = pkt_rate + * (desired_pkt_rate / pkt_rate) * usecs_per_sec = ITR value + * + * Assuming wmem_default is 212992 and overhead is 640 bytes per + * packet, (256 skb, 64 headroom, 320 shared info), we can reduce the + * formula down to: + * + * wmem_default * bits_per_byte * usecs_per_sec pkt_size + 24 + * ITR = -------------------------------------------- * -------------- + * rate pkt_size + 640 + */ +static unsigned int +ice_adjust_itr_by_size_and_speed(struct ice_port_info *port_info, + unsigned int avg_pkt_size, + unsigned int itr) { - switch (pi->phy.link_info.link_speed) { + switch (port_info->phy.link_info.link_speed) { + case ICE_AQ_LINK_SPEED_100GB: + itr += DIV_ROUND_UP(17 * (avg_pkt_size + 24), + avg_pkt_size + 640); + break; + case ICE_AQ_LINK_SPEED_50GB: + itr += DIV_ROUND_UP(34 * (avg_pkt_size + 24), + avg_pkt_size + 640); + break; case ICE_AQ_LINK_SPEED_40GB: - return ICE_ITR_ADAPTIVE_MIN_INC * 1024; + itr += DIV_ROUND_UP(43 * (avg_pkt_size + 24), + avg_pkt_size + 640); + break; case ICE_AQ_LINK_SPEED_25GB: + itr += DIV_ROUND_UP(68 * (avg_pkt_size + 24), + avg_pkt_size + 640); + break; case ICE_AQ_LINK_SPEED_20GB: - return ICE_ITR_ADAPTIVE_MIN_INC * 512; - case ICE_AQ_LINK_SPEED_100MB: - return ICE_ITR_ADAPTIVE_MIN_INC * 32; + itr += DIV_ROUND_UP(85 * (avg_pkt_size + 24), + avg_pkt_size + 640); + break; + case ICE_AQ_LINK_SPEED_10GB: + /* fall through */ default: - return ICE_ITR_ADAPTIVE_MIN_INC * 256; + itr += DIV_ROUND_UP(170 * (avg_pkt_size + 24), + avg_pkt_size + 640); + break; } + + if ((itr & ICE_ITR_MASK) > ICE_ITR_ADAPTIVE_MAX_USECS) { + itr &= ICE_ITR_ADAPTIVE_LATENCY; + itr += ICE_ITR_ADAPTIVE_MAX_USECS; + } + + return itr; } /** @@ -1128,8 +1178,8 @@ static unsigned int ice_itr_divisor(struct ice_port_info *pi) static void ice_update_itr(struct ice_q_vector *q_vector, struct ice_ring_container *rc) { - unsigned int avg_wire_size, packets, bytes, itr; unsigned long next_update = jiffies; + unsigned int packets, bytes, itr; bool container_is_rx; if (!rc->ring || !ITR_IS_DYNAMIC(rc->itr_setting)) @@ -1174,7 +1224,7 @@ ice_update_itr(struct ice_q_vector *q_vector, struct ice_ring_container *rc) if (packets && packets < 4 && bytes < 9000 && (q_vector->tx.target_itr & ICE_ITR_ADAPTIVE_LATENCY)) { itr = ICE_ITR_ADAPTIVE_LATENCY; - goto adjust_by_size; + goto adjust_by_size_and_speed; } } else if (packets < 4) { /* If we have Tx and Rx ITR maxed and Tx ITR is running in @@ -1242,70 +1292,11 @@ ice_update_itr(struct ice_q_vector *q_vector, struct ice_ring_container *rc) */ itr = ICE_ITR_ADAPTIVE_BULK; -adjust_by_size: - /* If packet counts are 256 or greater we can assume we have a gross - * overestimation of what the rate should be. Instead of trying to fine - * tune it just use the formula below to try and dial in an exact value - * gives the current packet size of the frame. - */ - avg_wire_size = bytes / packets; +adjust_by_size_and_speed: - /* The following is a crude approximation of: - * wmem_default / (size + overhead) = desired_pkts_per_int - * rate / bits_per_byte / (size + ethernet overhead) = pkt_rate - * (desired_pkt_rate / pkt_rate) * usecs_per_sec = ITR value - * - * Assuming wmem_default is 212992 and overhead is 640 bytes per - * packet, (256 skb, 64 headroom, 320 shared info), we can reduce the - * formula down to - * - * (170 * (size + 24)) / (size + 640) = ITR - * - * We first do some math on the packet size and then finally bitshift - * by 8 after rounding up. We also have to account for PCIe link speed - * difference as ITR scales based on this. - */ - if (avg_wire_size <= 60) { - /* Start at 250k ints/sec */ - avg_wire_size = 4096; - } else if (avg_wire_size <= 380) { - /* 250K ints/sec to 60K ints/sec */ - avg_wire_size *= 40; - avg_wire_size += 1696; - } else if (avg_wire_size <= 1084) { - /* 60K ints/sec to 36K ints/sec */ - avg_wire_size *= 15; - avg_wire_size += 11452; - } else if (avg_wire_size <= 1980) { - /* 36K ints/sec to 30K ints/sec */ - avg_wire_size *= 5; - avg_wire_size += 22420; - } else { - /* plateau at a limit of 30K ints/sec */ - avg_wire_size = 32256; - } - - /* If we are in low latency mode halve our delay which doubles the - * rate to somewhere between 100K to 16K ints/sec - */ - if (itr & ICE_ITR_ADAPTIVE_LATENCY) - avg_wire_size >>= 1; - - /* Resultant value is 256 times larger than it needs to be. This - * gives us room to adjust the value as needed to either increase - * or decrease the value based on link speeds of 10G, 2.5G, 1G, etc. - * - * Use addition as we have already recorded the new latency flag - * for the ITR value. - */ - itr += DIV_ROUND_UP(avg_wire_size, - ice_itr_divisor(q_vector->vsi->port_info)) * - ICE_ITR_ADAPTIVE_MIN_INC; - - if ((itr & ICE_ITR_MASK) > ICE_ITR_ADAPTIVE_MAX_USECS) { - itr &= ICE_ITR_ADAPTIVE_LATENCY; - itr += ICE_ITR_ADAPTIVE_MAX_USECS; - } + /* based on checks above packets cannot be 0 so division is safe */ + itr = ice_adjust_itr_by_size_and_speed(q_vector->vsi->port_info, + bytes / packets, itr); clear_counts: /* write back value */ |
