diff options
Diffstat (limited to 'include/linux/net_dim.h')
| -rw-r--r-- | include/linux/net_dim.h | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/include/linux/net_dim.h b/include/linux/net_dim.h new file mode 100644 index 000000000000..bebeaad897cc --- /dev/null +++ b/include/linux/net_dim.h @@ -0,0 +1,380 @@ +/* + * 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 */ |