diff options
Diffstat (limited to 'lib/dim/net_dim.c')
| -rw-r--r-- | lib/dim/net_dim.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/lib/dim/net_dim.c b/lib/dim/net_dim.c new file mode 100644 index 000000000000..5bcc902c5388 --- /dev/null +++ b/lib/dim/net_dim.c @@ -0,0 +1,190 @@ +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB +/* + * Copyright (c) 2018, Mellanox Technologies inc. All rights reserved. + */ + +#include <linux/dim.h> + +struct dim_cq_moder +net_dim_get_rx_moderation(u8 cq_period_mode, int ix) +{ + struct dim_cq_moder cq_moder = rx_profile[cq_period_mode][ix]; + + cq_moder.cq_period_mode = cq_period_mode; + return cq_moder; +} +EXPORT_SYMBOL(net_dim_get_rx_moderation); + +struct dim_cq_moder +net_dim_get_def_rx_moderation(u8 cq_period_mode) +{ + u8 profile_ix = cq_period_mode == DIM_CQ_PERIOD_MODE_START_FROM_CQE ? + NET_DIM_DEF_PROFILE_CQE : NET_DIM_DEF_PROFILE_EQE; + + return net_dim_get_rx_moderation(cq_period_mode, profile_ix); +} +EXPORT_SYMBOL(net_dim_get_def_rx_moderation); + +struct dim_cq_moder +net_dim_get_tx_moderation(u8 cq_period_mode, int ix) +{ + struct dim_cq_moder cq_moder = tx_profile[cq_period_mode][ix]; + + cq_moder.cq_period_mode = cq_period_mode; + return cq_moder; +} +EXPORT_SYMBOL(net_dim_get_tx_moderation); + +struct dim_cq_moder +net_dim_get_def_tx_moderation(u8 cq_period_mode) +{ + u8 profile_ix = cq_period_mode == DIM_CQ_PERIOD_MODE_START_FROM_CQE ? + NET_DIM_DEF_PROFILE_CQE : NET_DIM_DEF_PROFILE_EQE; + + return net_dim_get_tx_moderation(cq_period_mode, profile_ix); +} +EXPORT_SYMBOL(net_dim_get_def_tx_moderation); + +static int net_dim_step(struct dim *dim) +{ + if (dim->tired == (NET_DIM_PARAMS_NUM_PROFILES * 2)) + return DIM_TOO_TIRED; + + switch (dim->tune_state) { + case DIM_PARKING_ON_TOP: + case DIM_PARKING_TIRED: + break; + case DIM_GOING_RIGHT: + if (dim->profile_ix == (NET_DIM_PARAMS_NUM_PROFILES - 1)) + return DIM_ON_EDGE; + dim->profile_ix++; + dim->steps_right++; + break; + case DIM_GOING_LEFT: + if (dim->profile_ix == 0) + return DIM_ON_EDGE; + dim->profile_ix--; + dim->steps_left++; + break; + } + + dim->tired++; + return DIM_STEPPED; +} + +static void net_dim_exit_parking(struct dim *dim) +{ + dim->tune_state = dim->profile_ix ? DIM_GOING_LEFT : DIM_GOING_RIGHT; + net_dim_step(dim); +} + +static int net_dim_stats_compare(struct dim_stats *curr, + struct dim_stats *prev) +{ + if (!prev->bpms) + return curr->bpms ? DIM_STATS_BETTER : DIM_STATS_SAME; + + if (IS_SIGNIFICANT_DIFF(curr->bpms, prev->bpms)) + return (curr->bpms > prev->bpms) ? DIM_STATS_BETTER : + DIM_STATS_WORSE; + + if (!prev->ppms) + return curr->ppms ? DIM_STATS_BETTER : + DIM_STATS_SAME; + + if (IS_SIGNIFICANT_DIFF(curr->ppms, prev->ppms)) + return (curr->ppms > prev->ppms) ? DIM_STATS_BETTER : + DIM_STATS_WORSE; + + if (!prev->epms) + return DIM_STATS_SAME; + + if (IS_SIGNIFICANT_DIFF(curr->epms, prev->epms)) + return (curr->epms < prev->epms) ? DIM_STATS_BETTER : + DIM_STATS_WORSE; + + return DIM_STATS_SAME; +} + +static bool net_dim_decision(struct dim_stats *curr_stats, struct dim *dim) +{ + int prev_state = dim->tune_state; + int prev_ix = dim->profile_ix; + int stats_res; + int step_res; + + switch (dim->tune_state) { + case DIM_PARKING_ON_TOP: + stats_res = net_dim_stats_compare(curr_stats, + &dim->prev_stats); + if (stats_res != DIM_STATS_SAME) + net_dim_exit_parking(dim); + break; + + case DIM_PARKING_TIRED: + dim->tired--; + if (!dim->tired) + net_dim_exit_parking(dim); + break; + + case DIM_GOING_RIGHT: + case DIM_GOING_LEFT: + stats_res = net_dim_stats_compare(curr_stats, + &dim->prev_stats); + if (stats_res != DIM_STATS_BETTER) + dim_turn(dim); + + if (dim_on_top(dim)) { + dim_park_on_top(dim); + break; + } + + step_res = net_dim_step(dim); + switch (step_res) { + case DIM_ON_EDGE: + dim_park_on_top(dim); + break; + case DIM_TOO_TIRED: + dim_park_tired(dim); + break; + } + + break; + } + + if (prev_state != DIM_PARKING_ON_TOP || + dim->tune_state != DIM_PARKING_ON_TOP) + dim->prev_stats = *curr_stats; + + return dim->profile_ix != prev_ix; +} + +void net_dim(struct dim *dim, struct dim_sample end_sample) +{ + struct dim_stats curr_stats; + u16 nevents; + + switch (dim->state) { + case DIM_MEASURE_IN_PROGRESS: + nevents = BIT_GAP(BITS_PER_TYPE(u16), + end_sample.event_ctr, + dim->start_sample.event_ctr); + if (nevents < DIM_NEVENTS) + break; + dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats); + if (net_dim_decision(&curr_stats, dim)) { + dim->state = DIM_APPLY_NEW_PROFILE; + schedule_work(&dim->work); + break; + } + /* fall through */ + case DIM_START_MEASURE: + dim_update_sample(end_sample.event_ctr, end_sample.pkt_ctr, + end_sample.byte_ctr, &dim->start_sample); + dim->state = DIM_MEASURE_IN_PROGRESS; + break; + case DIM_APPLY_NEW_PROFILE: + break; + } +} +EXPORT_SYMBOL(net_dim); |