Yamin Friedman | f491545 | 2019-07-08 13:59:02 +0300 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB |
| 2 | /* |
| 3 | * Copyright (c) 2019, Mellanox Technologies inc. All rights reserved. |
| 4 | */ |
| 5 | |
| 6 | #include <linux/dim.h> |
| 7 | |
| 8 | static int rdma_dim_step(struct dim *dim) |
| 9 | { |
| 10 | if (dim->tune_state == DIM_GOING_RIGHT) { |
| 11 | if (dim->profile_ix == (RDMA_DIM_PARAMS_NUM_PROFILES - 1)) |
| 12 | return DIM_ON_EDGE; |
| 13 | dim->profile_ix++; |
| 14 | dim->steps_right++; |
| 15 | } |
| 16 | if (dim->tune_state == DIM_GOING_LEFT) { |
| 17 | if (dim->profile_ix == 0) |
| 18 | return DIM_ON_EDGE; |
| 19 | dim->profile_ix--; |
| 20 | dim->steps_left++; |
| 21 | } |
| 22 | |
| 23 | return DIM_STEPPED; |
| 24 | } |
| 25 | |
| 26 | static int rdma_dim_stats_compare(struct dim_stats *curr, |
| 27 | struct dim_stats *prev) |
| 28 | { |
| 29 | /* first stat */ |
| 30 | if (!prev->cpms) |
| 31 | return DIM_STATS_SAME; |
| 32 | |
| 33 | if (IS_SIGNIFICANT_DIFF(curr->cpms, prev->cpms)) |
| 34 | return (curr->cpms > prev->cpms) ? DIM_STATS_BETTER : |
| 35 | DIM_STATS_WORSE; |
| 36 | |
| 37 | if (IS_SIGNIFICANT_DIFF(curr->cpe_ratio, prev->cpe_ratio)) |
| 38 | return (curr->cpe_ratio > prev->cpe_ratio) ? DIM_STATS_BETTER : |
| 39 | DIM_STATS_WORSE; |
| 40 | |
| 41 | return DIM_STATS_SAME; |
| 42 | } |
| 43 | |
| 44 | static bool rdma_dim_decision(struct dim_stats *curr_stats, struct dim *dim) |
| 45 | { |
| 46 | int prev_ix = dim->profile_ix; |
| 47 | u8 state = dim->tune_state; |
| 48 | int stats_res; |
| 49 | int step_res; |
| 50 | |
| 51 | if (state != DIM_PARKING_ON_TOP && state != DIM_PARKING_TIRED) { |
| 52 | stats_res = rdma_dim_stats_compare(curr_stats, |
| 53 | &dim->prev_stats); |
| 54 | |
| 55 | switch (stats_res) { |
| 56 | case DIM_STATS_SAME: |
| 57 | if (curr_stats->cpe_ratio <= 50 * prev_ix) |
| 58 | dim->profile_ix = 0; |
| 59 | break; |
| 60 | case DIM_STATS_WORSE: |
| 61 | dim_turn(dim); |
Nick Desaulniers | 4c1ca83 | 2020-11-15 20:35:31 -0800 | [diff] [blame] | 62 | fallthrough; |
Yamin Friedman | f491545 | 2019-07-08 13:59:02 +0300 | [diff] [blame] | 63 | case DIM_STATS_BETTER: |
| 64 | step_res = rdma_dim_step(dim); |
| 65 | if (step_res == DIM_ON_EDGE) |
| 66 | dim_turn(dim); |
| 67 | break; |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | dim->prev_stats = *curr_stats; |
| 72 | |
| 73 | return dim->profile_ix != prev_ix; |
| 74 | } |
| 75 | |
| 76 | void rdma_dim(struct dim *dim, u64 completions) |
| 77 | { |
| 78 | struct dim_sample *curr_sample = &dim->measuring_sample; |
| 79 | struct dim_stats curr_stats; |
| 80 | u32 nevents; |
| 81 | |
| 82 | dim_update_sample_with_comps(curr_sample->event_ctr + 1, 0, 0, |
| 83 | curr_sample->comp_ctr + completions, |
| 84 | &dim->measuring_sample); |
| 85 | |
| 86 | switch (dim->state) { |
| 87 | case DIM_MEASURE_IN_PROGRESS: |
| 88 | nevents = curr_sample->event_ctr - dim->start_sample.event_ctr; |
| 89 | if (nevents < DIM_NEVENTS) |
| 90 | break; |
Roy Novich | 162bd18 | 2023-05-07 16:57:43 +0300 | [diff] [blame] | 91 | if (!dim_calc_stats(&dim->start_sample, curr_sample, &curr_stats)) |
| 92 | break; |
Yamin Friedman | f491545 | 2019-07-08 13:59:02 +0300 | [diff] [blame] | 93 | if (rdma_dim_decision(&curr_stats, dim)) { |
| 94 | dim->state = DIM_APPLY_NEW_PROFILE; |
| 95 | schedule_work(&dim->work); |
| 96 | break; |
| 97 | } |
Nick Desaulniers | 4c1ca83 | 2020-11-15 20:35:31 -0800 | [diff] [blame] | 98 | fallthrough; |
Yamin Friedman | f491545 | 2019-07-08 13:59:02 +0300 | [diff] [blame] | 99 | case DIM_START_MEASURE: |
| 100 | dim->state = DIM_MEASURE_IN_PROGRESS; |
| 101 | dim_update_sample_with_comps(curr_sample->event_ctr, 0, 0, |
| 102 | curr_sample->comp_ctr, |
| 103 | &dim->start_sample); |
| 104 | break; |
| 105 | case DIM_APPLY_NEW_PROFILE: |
| 106 | break; |
| 107 | } |
| 108 | } |
| 109 | EXPORT_SYMBOL(rdma_dim); |