/* * Copyright (c) 2016, Mellanox Technologies. All rights reserved. * Copyright (c) 2017-2018, Broadcom Limited. All rights reserved. * * This software is available to you under a choice of one of two * licenses. You may choose to be licensed under the terms of the GNU * General Public License (GPL) Version 2, available from the file * COPYING in the main directory of this source tree, or the * OpenIB.org BSD license below: * * Redistribution and use in source and binary forms, with or * without modification, are permitted provided that the following * conditions are met: * * - Redistributions of source code must retain the above * copyright notice, this list of conditions and the following * disclaimer. * * - Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials * provided with the distribution. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #ifndef NET_DIM_H #define NET_DIM_H #include <linux/module.h> struct net_dim_cq_moder { u16 usec; u16 pkts; u8 cq_period_mode; }; struct net_dim_sample { ktime_t time; u32 pkt_ctr; u32 byte_ctr; u16 event_ctr; }; struct net_dim_stats { int ppms; /* packets per msec */ int bpms; /* bytes per msec */ int epms; /* events per msec */ }; struct net_dim { /* Adaptive Moderation */ u8 state; struct net_dim_stats prev_stats; struct net_dim_sample start_sample; struct work_struct work; u8 profile_ix; u8 mode; u8 tune_state; u8 steps_right; u8 steps_left; u8 tired; }; enum { NET_DIM_CQ_PERIOD_MODE_START_FROM_EQE = 0x0, NET_DIM_CQ_PERIOD_MODE_START_FROM_CQE = 0x1, NET_DIM_CQ_PERIOD_NUM_MODES }; /* Adaptive moderation logic */ enum { NET_DIM_START_MEASURE, NET_DIM_MEASURE_IN_PROGRESS, NET_DIM_APPLY_NEW_PROFILE, }; enum { NET_DIM_PARKING_ON_TOP, NET_DIM_PARKING_TIRED, NET_DIM_GOING_RIGHT, NET_DIM_GOING_LEFT, }; enum { NET_DIM_STATS_WORSE, NET_DIM_STATS_SAME, NET_DIM_STATS_BETTER, }; enum { NET_DIM_STEPPED, NET_DIM_TOO_TIRED, NET_DIM_ON_EDGE, }; #define NET_DIM_PARAMS_NUM_PROFILES 5 /* Adaptive moderation profiles */ #define NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE 256 #define NET_DIM_DEF_PROFILE_CQE 1 #define NET_DIM_DEF_PROFILE_EQE 1 /* All profiles sizes must be NET_PARAMS_DIM_NUM_PROFILES */ #define NET_DIM_EQE_PROFILES { \ {1, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \ {8, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \ {64, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \ {128, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \ {256, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \ } #define NET_DIM_CQE_PROFILES { \ {2, 256}, \ {8, 128}, \ {16, 64}, \ {32, 64}, \ {64, 64} \ } static const struct net_dim_cq_moder profile[NET_DIM_CQ_PERIOD_NUM_MODES][NET_DIM_PARAMS_NUM_PROFILES] = { NET_DIM_EQE_PROFILES, NET_DIM_CQE_PROFILES, }; static inline struct net_dim_cq_moder net_dim_get_profile(u8 cq_period_mode, int ix) { struct net_dim_cq_moder cq_moder; cq_moder = profile[cq_period_mode][ix]; cq_moder.cq_period_mode = cq_period_mode; return cq_moder; } static inline struct net_dim_cq_moder net_dim_get_def_profile(u8 rx_cq_period_mode) { int default_profile_ix; if (rx_cq_period_mode == NET_DIM_CQ_PERIOD_MODE_START_FROM_CQE) default_profile_ix = NET_DIM_DEF_PROFILE_CQE; else /* NET_DIM_CQ_PERIOD_MODE_START_FROM_EQE */ default_profile_ix = NET_DIM_DEF_PROFILE_EQE; return net_dim_get_profile(rx_cq_period_mode, default_profile_ix); } static inline bool net_dim_on_top(struct net_dim *dim) { switch (dim->tune_state) { case NET_DIM_PARKING_ON_TOP: case NET_DIM_PARKING_TIRED: return true; case NET_DIM_GOING_RIGHT: return (dim->steps_left > 1) && (dim->steps_right == 1); default: /* NET_DIM_GOING_LEFT */ return (dim->steps_right > 1) && (dim->steps_left == 1); } } static inline void net_dim_turn(struct net_dim *dim) { switch (dim->tune_state) { case NET_DIM_PARKING_ON_TOP: case NET_DIM_PARKING_TIRED: break; case NET_DIM_GOING_RIGHT: dim->tune_state = NET_DIM_GOING_LEFT; dim->steps_left = 0; break; case NET_DIM_GOING_LEFT: dim->tune_state = NET_DIM_GOING_RIGHT; dim->steps_right = 0; break; } } static inline int net_dim_step(struct net_dim *dim) { if (dim->tired == (NET_DIM_PARAMS_NUM_PROFILES * 2)) return NET_DIM_TOO_TIRED; switch (dim->tune_state) { case NET_DIM_PARKING_ON_TOP: case NET_DIM_PARKING_TIRED: break; case NET_DIM_GOING_RIGHT: if (dim->profile_ix == (NET_DIM_PARAMS_NUM_PROFILES - 1)) return NET_DIM_ON_EDGE; dim->profile_ix++; dim->steps_right++; break; case NET_DIM_GOING_LEFT: if (dim->profile_ix == 0) return NET_DIM_ON_EDGE; dim->profile_ix--; dim->steps_left++; break; } dim->tired++; return NET_DIM_STEPPED; } static inline void net_dim_park_on_top(struct net_dim *dim) { dim->steps_right = 0; dim->steps_left = 0; dim->tired = 0; dim->tune_state = NET_DIM_PARKING_ON_TOP; } static inline void net_dim_park_tired(struct net_dim *dim) { dim->steps_right = 0; dim->steps_left = 0; dim->tune_state = NET_DIM_PARKING_TIRED; } static inline void net_dim_exit_parking(struct net_dim *dim) { dim->tune_state = dim->profile_ix ? NET_DIM_GOING_LEFT : NET_DIM_GOING_RIGHT; net_dim_step(dim); } #define IS_SIGNIFICANT_DIFF(val, ref) \ (((100 * abs((val) - (ref))) / (ref)) > 10) /* more than 10% difference */ static inline int net_dim_stats_compare(struct net_dim_stats *curr, struct net_dim_stats *prev) { if (!prev->bpms) return curr->bpms ? NET_DIM_STATS_BETTER : NET_DIM_STATS_SAME; if (IS_SIGNIFICANT_DIFF(curr->bpms, prev->bpms)) return (curr->bpms > prev->bpms) ? NET_DIM_STATS_BETTER : NET_DIM_STATS_WORSE; if (!prev->ppms) return curr->ppms ? NET_DIM_STATS_BETTER : NET_DIM_STATS_SAME; if (IS_SIGNIFICANT_DIFF(curr->ppms, prev->ppms)) return (curr->ppms > prev->ppms) ? NET_DIM_STATS_BETTER : NET_DIM_STATS_WORSE; if (!prev->epms) return NET_DIM_STATS_SAME; if (IS_SIGNIFICANT_DIFF(curr->epms, prev->epms)) return (curr->epms < prev->epms) ? NET_DIM_STATS_BETTER : NET_DIM_STATS_WORSE; return NET_DIM_STATS_SAME; } static inline bool net_dim_decision(struct net_dim_stats *curr_stats, struct net_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 NET_DIM_PARKING_ON_TOP: stats_res = net_dim_stats_compare(curr_stats, &dim->prev_stats); if (stats_res != NET_DIM_STATS_SAME) net_dim_exit_parking(dim); break; case NET_DIM_PARKING_TIRED: dim->tired--; if (!dim->tired) net_dim_exit_parking(dim); break; case NET_DIM_GOING_RIGHT: case NET_DIM_GOING_LEFT: stats_res = net_dim_stats_compare(curr_stats, &dim->prev_stats); if (stats_res != NET_DIM_STATS_BETTER) net_dim_turn(dim); if (net_dim_on_top(dim)) { net_dim_park_on_top(dim); break; } step_res = net_dim_step(dim); switch (step_res) { case NET_DIM_ON_EDGE: net_dim_park_on_top(dim); break; case NET_DIM_TOO_TIRED: net_dim_park_tired(dim); break; } break; } if ((prev_state != NET_DIM_PARKING_ON_TOP) || (dim->tune_state != NET_DIM_PARKING_ON_TOP)) dim->prev_stats = *curr_stats; return dim->profile_ix != prev_ix; } static inline void net_dim_sample(u16 event_ctr, u64 packets, u64 bytes, struct net_dim_sample *s) { s->time = ktime_get(); s->pkt_ctr = packets; s->byte_ctr = bytes; s->event_ctr = event_ctr; } #define NET_DIM_NEVENTS 64 #define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE) #define BIT_GAP(bits, end, start) ((((end) - (start)) + BIT_ULL(bits)) & (BIT_ULL(bits) - 1)) static inline void net_dim_calc_stats(struct net_dim_sample *start, struct net_dim_sample *end, struct net_dim_stats *curr_stats) { /* u32 holds up to 71 minutes, should be enough */ u32 delta_us = ktime_us_delta(end->time, start->time); u32 npkts = BIT_GAP(BITS_PER_TYPE(u32), end->pkt_ctr, start->pkt_ctr); u32 nbytes = BIT_GAP(BITS_PER_TYPE(u32), end->byte_ctr, start->byte_ctr); if (!delta_us) return; curr_stats->ppms = DIV_ROUND_UP(npkts * USEC_PER_MSEC, delta_us); curr_stats->bpms = DIV_ROUND_UP(nbytes * USEC_PER_MSEC, delta_us); curr_stats->epms = DIV_ROUND_UP(NET_DIM_NEVENTS * USEC_PER_MSEC, delta_us); } static inline void net_dim(struct net_dim *dim, struct net_dim_sample end_sample) { struct net_dim_stats curr_stats; u16 nevents; switch (dim->state) { case NET_DIM_MEASURE_IN_PROGRESS: nevents = BIT_GAP(BITS_PER_TYPE(u16), end_sample.event_ctr, dim->start_sample.event_ctr); if (nevents < NET_DIM_NEVENTS) break; net_dim_calc_stats(&dim->start_sample, &end_sample, &curr_stats); if (net_dim_decision(&curr_stats, dim)) { dim->state = NET_DIM_APPLY_NEW_PROFILE; schedule_work(&dim->work); break; } /* fall through */ case NET_DIM_START_MEASURE: dim->state = NET_DIM_MEASURE_IN_PROGRESS; break; case NET_DIM_APPLY_NEW_PROFILE: break; } } #endif /* NET_DIM_H */